Answer:
At a significance level of 0.05, there is enough evidence to claim that there is a significant relationship between x and y.
P-value = 0.003.
Step-by-step explanation:
If we perform a regression analysis relating x and y, we get the best fitting line with equation:
[tex]y=15.82x+92.9[/tex]
and a correlation coefficient r:
[tex]r=0.693[/tex]
We have to test the hypothesis, where the alternative hypothesis claims that there is a relationship between these two variables, and the null hypothesis claiming there is no relationship (meaning that the correlation is not significantly different from 0).
This can be written as:
[tex]H_0: \rho=0\\\\H_a:\rho\neq0[/tex]
where ρ is the population correlation coefficient for x and y.
The significance level is assumed to be 0.05.
The sample size is n=16.
The degrees of freedom are df=14.
[tex]df=n-2=16-2=14[/tex]
The test statistic can be calculated as:
[tex]t=\dfrac{r\sqrt{n-2}}{\sqrt{1-r^2}}=\dfrac{0.693\sqrt{14}}{\sqrt{1-(0.693)^2}}=\dfrac{2.593}{0.721}=3.597[/tex]
For a test statistic t=2.05 and 14 degrees of freedom, the P-value is calculated as:
[tex]\text{P-value}=2\cdot P(t>3.597)=0.003[/tex]
The P-value (0.003) is smaller than the significance level (0.05), so the effect is significant enough.
The null hypothesis is rejected.
At a significance level of 0.05, there is enough evidence to claim that there is a significant relationship between x and y.
9. In 2002 the Georgia department of education reported a mean reading test score of 850 from Tattnall County Career Academy with a standard deviation of 50. The sample was taken from 100 11th grade students. Assuming the test scores are normally distributed, what is the standard error
Answer:
The standard error = 5
Step-by-step explanation:
Explanation:-
Given sample size 'n' = 100
Given mean reading test score μ = 850
Given standard deviation of the population 'σ' = 50
The standard error is determined by
Standard error = [tex]\frac{S.D}{\sqrt{n} }[/tex]
S.E = σ/√n
[tex]S.E = \frac{S.D}{\sqrt{n} } = \frac{50}{\sqrt{100} } = 5[/tex]
Final answer:-
The standard error ( S.E) = 5
Do the points shown represent additive inverses? Explain why or why not
Answer:
Yes additive inverse is two complete opposite numbers if added = 0
Answer:
additive
Step-by-step explanation:
Because the point is not past the postive live or below the negative.
A population of beetles are growing according to a linear growth model. The initial population (week 0) is
P0=6, and the population after 8 weeks is P8=86 Find an explicit formula for the beetle population after n weeks.
After how many weeks will the beetle population reach 236?
Answer:
The number of weeks it will take for the beetle population to reach 236 is 28.75.
Step-by-step explanation:
If a quantity starts at size P₀ and grows by d every time period, then the
quantity after n time periods can be determined using explicit form:
[tex]P_{n} = P_{0} + d \cdot n[/tex]
Here,
d = the common difference, i.e. the amount that the population changes each time n is increased by 1.
In this case it is provided that the original population of beetle was:
P₀ = 6; (week 0)
And the population after 8 weeks was,
P₈ = 86
Compute the value of d as follows:
[tex]P_{8} = P_{0} + d \cdot 8\\86=6+8d\\86-6=8d\\80=8d\\d=10[/tex]
Thus, the explicit formula for the beetle population after n weeks is:
[tex]P_{n}=P_{0}+8n[/tex]
Compute the number of weeks it will take for the beetle population to reach 236 as follows:
[tex]P_{n}=P_{0}+8n\\\\236=6+8n\\\\8n=236-6\\\\8n=230\\\\n=28.75[/tex]
Thus, the number of weeks it will take for the beetle population to reach 236 is 28.75.
The population P of a culture of Pseudomonas aeruginosa bacteria is given by P = −1718t2 + 82,000t + 10,000, where t is the time in hours since the culture was started. Determine the time(s) at which the population was 600,000. Round to the nearest hour.
Answer:
Rounding to the nearest hour, the times at which the population was 600,000 was at 9 hours and at 39 hours.
Step-by-step explanation:
Determine the time(s) at which the population was 600,000.
This is t for which P(t) = 600000. To do this, we solve a quadratic equation.
Solving a quadratic equation:
Given a second order polynomial expressed by the following equation:
[tex]ax^{2} + bx + c, a\neq0[/tex].
This polynomial has roots [tex]x_{1}, x_{2}[/tex] such that [tex]ax^{2} + bx + c = a(x - x_{1})*(x - x_{2})[/tex], given by the following formulas:
[tex]x_{1} = \frac{-b + \sqrt{\bigtriangleup}}{2*a}[/tex]
[tex]x_{2} = \frac{-b - \sqrt{\bigtriangleup}}{2*a}[/tex]
[tex]\bigtriangleup = b^{2} - 4ac[/tex]
In this question:
[tex]P(t) = -1718t^{2} + 82000t + 10000[/tex]
We have to find t for which P(t) = 600000. Then
[tex]600000 = -1718t^{2} + 82000t + 10000[/tex]
[tex]-1718t^{2} + 82000t - 590000 = 0[/tex]
So [tex]a = -1718, b = 82000, c = -590000[/tex]
Then
[tex]\bigtriangleup = 82000^{2} - 4*(-1718)*(-590000) = 2669520000[/tex]
[tex]t_{1} = \frac{-82000 + \sqrt{2669520000}}{2*(-1718)} = 8.8[/tex]
[tex]t_{2} = \frac{-82000 - \sqrt{2669520000}}{2*(-1718)} = 38.9[/tex]
Rounding to the nearest hour, the times at which the population was 600,000 was at 9 hours and at 39 hours.
Jenn uses 6 cups of flour to bake 40 muffins. How many muffins can she can bake if she has 15 cups of flour?
Answer:
100 muffins
Step-by-step explanation:
We can use a ratio to solve
6 cups 15 cups
------------- = -----------
40 muffins x muffins
Using cross products
6x = 40*15
Divide each side by 6
6x/6 = 40*15/6
x =100
100 muffins
Answer:
100 muffins
Step-by-step explanation:
If she could bake 40 muffins with 6 cups, then she could bake 80 muffins with 12 cups. Then, we have 3 cups left over, which is half of 6, meaning she can only bake half of her regular amount with 3 cups, which would be 20. 80+20=100
40+40+20=100
The original price of a mountain bike was reduced by $125.
If p= the mountain bike's original price in dollars, which algebraic expression
represents the reduced price?
Answer:
p-125
Step-by-step explanation:
p represents the original price, which was reduced by 125. therefore, the reduced price is represented by the algebraic expression p-125
Answer: p - 125
Step-by-step explanation: Here, notice that the value that we don't know is the mountain bike's original price in dollars.
Since the original price of the mountain bike was reduced by $125,
we take away 125 from our variable, which is p.
So we have p - 125.
Brian invests £6300 into his bank account.
He receives 4.9% per year compound interest.
How much will Brian have after 2 years?
Give your answer to the nearest penny where appropriate.
Answer:
Amount that Brian has after 2 years = £6932.53
Step-by-step explanation:
To find, the amount that Brian will have after 2 years:
Formula for amount where compound interest is applicable:
[tex]A = P \times (1+\dfrac{R}{100})^t[/tex]
Where A is the amount after t years time
P is the principal.
R is the rate of interest.
In the question, we are given the following details:
Principal amount,P = £6300
Rate of interest,R = 4.9%
Time,t = 2 years
Putting the values in formula:
[tex]A = 6300 \times (1+\dfrac{4.9}{100})^2\\\Rightarrow 6300 \times (\dfrac{104.9}{100})^2\\\Rightarrow 6932.53[/tex]
Hence, Amount that Brian has after 2 years = £6932.53
Answer:
THE ANSWER IS ABOVE
Step-by-step explanation:
hahahaha
B
ABC is a right-angled triangle.
AC = 16 cm
Angle C = 90°
А.
size of angle B : size of angle A = 3:2
С
16 cm
Work out the length of AB.
Give your answer correct to 3 significant figures.
Answer:
19.8 cm
Step-by-step explanation:
Angle B is the complement of angle A, so we have this relation for the angles:
B/A = 3/2 = (90°-A)/A
2(90° -A) = 3A . . . . . cross multiply
180° = 5A . . . . . . . . . eliminate parentheses, add 2A
36° = A . . . . . . . . . . . divide by 5
The relations expressed by the mnemonic SOH CAH TOA remind you that ...
Cos = Adjacent/Hypotenuse
cos(A) = AC/AB
AB = AC/cos(A) = (16 cm)/cos(36°)
AB ≈ 19.8 cm
What is 2/3 divided 1/6 ?
Answer: 4
Step-by-step explanation:
in order to divide one fraction by another, you must multiply by the reciprocal(the reverse of a certain fraction). the reciprocal of 1/6 is 6/1. so:
[tex]\frac{2}{3} / \frac{1}{6}[/tex] = multiply by the reciprocal of 1/6
[tex]\frac{2}{3} * \frac{6}{1}[/tex] = cross out
[tex]\frac{2}{1} * \frac{2}{1}[/tex] = multiply
[tex]\frac{4}{1}[/tex] = simplify
4
Answer:
4
Step-by-step explanation:
(2/3)/(1/6)
Eleminate the denominator by multiplying numerator and denominator with whatever is the reciprocal of the denominator. In this case the denominator is 1/6 so the reciprocal is 6/1 or "just" 6.
So, multiply numerator and denominator by 6. The next three (bold) steps, have been written down for explanatory purposes only, and normally are not nessasary.
(2/3)*6 / (1/6)*6
(2/3)*6 / (6/6)
(2/3)*6 / 1
(2/3)*6
12/3
4
What’s the Midpoint of (2,-1) and (1,-2)
Answer:
(3/2,-3/2)
Step-by-step explanation:
The midpoint of (2,-1)(1,-2) is (3/2,-3/2)
Answer:
(1.5,-1.5)
You have to remember the formula to find mid-point and that is:
[tex]midpoint = ( \frac{x1 + x2}{2} ,\frac{y1 + y2}{2} )[/tex]
please see the attached picture for full solution
Hope it helps
Good luck on your assignment
An AP news service story, printed in the Gainesville Sun on May 20, 1979, states the following with regard to debris from Skylab striking someone on the ground: "The odds are 1 in 150 that a piece of Skylab will hit someone. But 4 billion people ... live in the zone in which pieces could fall. So any one person’s chances of being struck are one in 150 times 4 billion—or one in 600 billion." Do you see any inaccuracies in this reasoning?
Answer:
The odds are one in approximately 27 million.Not one in 600 billionStep-by-step explanation:
From the news story, we are told that:
The odds are 1 in 150 that a piece of Skylab will hit someone.
However, 4 billion people live in the zone in which pieces could fall.
Therefore, any one person’s chances of being struck are:
[tex]=\dfrac{1}{150} \times 4$ billion\\=\dfrac{1}{37.5}$ billion\\\\=26,666,667 million[/tex]
Therefore, the odds are one in approximately 27 million.
The inaccuracy presented in this reasoning was that the odds are one in 600 billion.
= [70 + (-30)] + [2 + (-9)] + [0.3 + (-0.10]
Answer:
33.2
Step-by-step explanation:
70−30+2−9+0.3−0.1
=40+2−9+0.3−0.1
=40+−7+0.3−0.1
=33+0.3−0.1
=33+0.2
=33.2
Answer:
33.2
Step-by-step explanation
If we start from the left and work our way right:
70+(-30) is the same as 70-30 which would give 40
2+(-9) is the same as 2-9 which would give -7
0.3(-0.1) is the same as 0.3-0.1 which would give 0.2
now if you put them together
40-7+.2 gives 33.2
can someone please help meee!???
What’s the correct answer for this?
Answer:
D.
Step-by-step explanation:
If we rotate the 3-D figure around y-axis, we'll obtain a cylinder with a radius of 1 unit.
Using the following data on the Observations 10, 13, 4, and 20 confirm that the complete linkage distance between the cluster containing 《10, 13) and the cluster containing (4, 20) s 2.577 units as displayed in the dendrogram
Observation
13 20 0.032 0.195 -0510 0.466 0.741 0.8750.207 0.474 0.700 0.748 -0.004 -0.490 -0.892 0.735 0.219 0.655 -0.1731.013 0.943 0.083 -0.693 -0.489-0.702 -0.458 1.620 2.275 1328 1.733 -0.863 1.035 0.724 0.721 10 Income/Debt Return Cost Load Peak Sales TotalFuelCosts
If required, round your answers to three decimal places.Do not round intermediate calculations
1. Distance from Observation 10 and Observation 4:
2. Distance from Observation 10 and Observation 20:
3. Distance from Observation 13 and Observation 4:
4. Distance from Observation 13 and Observation 20:
Answer:
Step-by-step explanation:
The distance between:
10 and 4: 1.492
10 and 20: 2.055
13 and 4: 2.577
13 and 20: 2.226
The R code:
#Convert your datafile into csv and make sure your row names are 10,13,4 and 20
data=read.csv(file.choose())
data
row.names(data)=c(10,13,4,20)
data
d=dist(data,method="euclidean")
d
fit=hclust(d,method="complete")
plot(fit)
groups=cutree(fit,k=2)
rect.hclust(fit,k=2,border="red")
After a long study, tree scientists conclude that a eucalyptus tree will grow at the rate of 0.5 6/ (t+4)3 feet per year, where t is the time (in years)
(a) Find the number of feet that the tree will grow in the second year.
(b) Find the number of feet the tree will grow in the third year.
(c) The total number of feet grown during the second year is_____________ ft.
Answer:
a) 0.5367feetb) 0.5223feetc) 0.7292feetStep-by-step explanation:
Given the rate at which an eucalyptus tree will grow modelled by the equation 0.5+6/(t+4)³ feet per year, where t is the time (in years).
The amount of growth can be gotten by integrating the given rate equation as shown;
[tex]\int\limits {0.5 + \frac{6}{(t+4)^{3} } } \, dt \\= \int\limits {0.5} \, dt + \int\limits\frac{6}{(t+4)^{3} } } \, dx } \, \\= 0.5t +\int\limits {6u^{-3} } \, du \ where \ u = t+4 \ and\ du = dt\\= 0.5t + 6*\frac{u^{-2} }{-2} + C\\= 0.5t-3u^{-2} +C\\= 0.5t-3(t+4)^{-2} + C[/tex]
a) The number of feet that the tree will grow in the second year can be gotten by taking the limit of the integral from t =1 to t = 2
[tex]\int\limits^2_1 {0.5 + \frac{6}{(t+4)^{3} } } \, dt = [0.5t-3(t+4)^{-2}]^2_1\\= [0.5(2)-3(2+4)^{-2}] - [0.5(1)-3(1+4)^{-2}]\\= [1-3(6)^{-2}] - [0.5-3(5)^{-2}]\\ = [1-\frac{1}{12}] - [0.5-\frac{3}{25} ]\\= \frac{11}{12}-\frac{1}{2}+\frac{3}{25}\\ = 0.9167 - 0.5 + 0.12\\= 0.5367feet[/tex]
b) The number of feet that the tree will grow in the third year can be gotten by taking the limit of the integral from t =2 to t = 3
[tex]\int\limits^3_2 {0.5 + \frac{6}{(t+4)^{3} } } \, dt = [0.5t-3(t+4)^{-2}]^3_2\\= [0.5(3)-3(3+4)^{-2}] - [0.5(2)-3(2+4)^{-2}]\\= [1.5-3(7)^{-2}] - [1-3(6)^{-2}]\\ = [1.5-\frac{3}{49}] - [1-\frac{1}{12} ]\\ = 1.439 - 0.9167\\= 0.5223feet[/tex]
c) The total number of feet grown during the second year can be gotten by substituting the value of limit from t = 0 to t = 2 into the equation as shown
[tex]\int\limits^2_0 {0.5 + \frac{6}{(t+4)^{3} } } \, dt = [0.5t-3(t+4)^{-2}]^2_0\\= [0.5(2)-3(2+4)^{-2}] - [0.5(0)-3(0+4)^{-2}]\\= [1-3(6)^{-2}] - [0-3(4)^{-2}]\\ = [1-\frac{1}{12}] - [-\frac{3}{16} ]\\= \frac{11}{12}+\frac{3}{16}\\ = 0.9167 - 0.1875\\= 0.7292feet[/tex]
Identify the level of measurement of the data, and explain what is wrong with the given calculation. In a survey, the favorite sports of respondents are identified as 100 for basketball comma 200 for baseball comma 300 for football comma and 400 for anything else. The average (mean) is calculated for 597 respondents and the result is 256.1 .The data are at the _________________
level of measurement.
Answer:
The data are at the Nominal level of measurement.
The given calculation is wrong because average (mean) cannot be calculated for nominal level of measurement.
Step-by-step explanation:
The objective here is to Identify the level of measurement of the data, and explain what is wrong with the given calculation.
a)
The data are at the Nominal level of measurement due to the fact that it portrays the qualitative levels of naming and representing different hierarchies from 100 basketball, 200 basketball, 300 football, 400 anything else
b) We are being informed that, the average (mean) is calculated for 597 respondents and the result is 256.1.
The given calculation is wrong because average (mean) cannot be calculated for nominal level of measurement. At nominal level this type of data set do not measure at all , it is not significant to compute their average (mean).
A rectangular deck is 12 ft by 14 ft. When the length and width are increased by the same amount, the area becomes 288 sq. Ft. How much were the dimensions increased?
Answer:
4 ft
Step-by-step explanation:
288=16 * 18
12+4=16
14+4=18
The dimensions increased by 4 feet.
What is the area of the rectangle?The area of the rectangle is the product of the length and width of a given rectangle.
The area of the rectangle = length × Width
Given;
Dimensions of rectangle = 12 + x and 14 + x
The area of the rectangle= (12 + x) (14 + x) = 288
x² + 26x + 168 = 288
x² + 26x - 120 = 0
(x + 30) (x - 4) = 0
x=-30, x =4
Hence, The dimensions increased by 4 feet.
Learn more about the area;
https://brainly.com/question/1658516
#SPJ2
Find the value of z
Answer:
87°
Step-by-step explanation:
In the given figure, a quadrilateral is inscribed in a circle. Therefore, it is a cyclic quadrilateral.
Opposite angles of a cyclic quadrilateral are supplementary.
[tex] \therefore \: z + 93 \degree = 180 \degree \\ \therefore \: z = 180 \degree - 93 \degree \\ \huge \red{ \boxed{\therefore \: z = 87 \degree}}[/tex]
Given fix) = 3x- 1 and g(x) = 2x-3, for which value of x does g(x) = f(2)?
X=
2
О
X= 2
NDI
X=
x=4
Answer:
The value of X would be 4.
Answer:
x=4
Step-by-step explanation:
f(2)=3*2-1=5
g(x)=2x-3=5
2x=8
x=4
ASAP! GIVING BRAINLIEST! Please read the question THEN answer CORRECTLY! NO guessing. I say no guessing because people usually guess on my questions.
Answer:
B. (f - g)(x) = [tex]3^x-2x+14[/tex]
Step-by-step explanation:
→Set it up, like so:
[tex](3^x+10)-(2x-4)[/tex]
→Distribute the -1 to (2x - 4):
[tex]3^x+10-2x+4[/tex]
→Add like terms (10 and 4):
[tex]3^x-2x+14[/tex]
Lola bought x pencils that cost $0.25 each and y erasers that cost $0.50. She spent less than $3. Which graph represents Lola’s purchase?
Answer:
Graph C is the answer.
Step-by-step explanation:
Lola bought X pencils that cost $0.25 and Y erasers that cost $0.50.
Total expenditure is less than $3.
If we represent expense in the equation form then it will be
Expense on pencils + expense on erasers = Total expense which is < 3
0.25X + 0.50Y < 3
Now we divide the inequality by 0.25
X + 2Y < 12
This inequality when graphed, line will be plotted in dots and area below the line will be in the shaded form.
Slope of this line is = (-1/2) {from the standard equation of line y = mx + c)
Now we come to the graphs. Here dotted line graphs are A or C.
We will calculate the slopes of the lines from the graphs A and C to get tha answer.
For Graph A
The end points are (12, 0) and (0, 3)
So slope = (y-y')/(x-x') = (3-0)/(0-12) = -3/12 = -1/4
For Graph C.
End points the line are (0, 6) and (12, 0)
Slope of the line = (0-6)/(12-0) = -6/12 = -1/2
Therefore Graph C is the answer.
Answer:
Graph C is the answer.
Step-by-step explanation:
Lola bought X pencils that cost $0.25 and Y erasers that cost $0.50.
Total expenditure is less than $3.
If we represent expense in the equation form then it will be
Expense on pencils + expense on erasers = Total expense which is < 3
0.25X + 0.50Y < 3
Now we divide the inequality by 0.25
X + 2Y < 12
This inequality when graphed, line will be plotted in dots and area below the line will be in the shaded form.
Slope of this line is = (-1/2) {from the standard equation of line y = mx + c)
Now we come to the graphs. Here dotted line graphs are A or C.
We will calculate the slopes of the lines from the graphs A and C to get tha answer.
For Graph A
The end points are (12, 0) and (0, 3)
So slope = (y-y')/(x-x') = (3-0)/(0-12) = -3/12 = -1/4
For Graph C.
End points the line are (0, 6) and (12, 0)
Slope of the line = (0-6)/(12-0) = -6/12 = -1/2
Therefore Graph C is the answer.
Step-by-step explanation:
make brainiest please
2x + 3=-7?what is this even mean
Answer:
2 times some thing and plus 3 equals -7
Step-by-step explanation:
x = -5
An eight-sided die, which may or may not be a fair die, has four colors on it; you have been tossing the die for an hour and have recorded the color rolled for each toss. What is the probability you will roll a green on your next toss of the die? Express your answer as a simplified fraction or a decimal rounded to four decimal places.
The complete question is;
An eight-sided die, which may or may not be a fair die, has four colors on it; you have been tossing the die for an hour and have recorded the color rolled for each toss. What is the probability you will roll a green on your next toss of the die? Express your answer as a simplified fraction or a decimal rounded to four decimal places.
orange brown green yellow
46 23 32 19
Answer:
probability of rolling green on the next toss of the die = 4/15
Step-by-step explanation:
We are given how many times each of the colours appeared for each toss and they are;
Orange - 46
Brown - 23
Green - 32
Yellow - 19
Thus,
Total number of tosses = 46 + 23 + 32 + 19 = 120 rolls
Thus, probability of rolling green on the next toss of die will be = number of times green appeared/total number of rolls = 32/120 = 4/15
The escape time (sec) for oil workers in a simulated exercise, gave the sample mean 370.69, sample standard deviation 24.36, and number of observations as n =26. Suppose the investigators had believed a priori that true average escape time would be at most 6 minutes. Does the data contradict this prior belief? Assuming normality, test the appropriate hypothesis using a significance level of .05.
Answer:
Null hypothesis:[tex]\mu \leq 6[/tex]
Alternative hypothesis:[tex]\mu > 6[/tex]
The statistic is given by:
[tex]t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}[/tex] (1)
Replacing the info we got:
[tex]t=\frac{6.178-6}{\frac{0.68}{\sqrt{26}}}=1.335[/tex]
[tex]p_v =P(t_{25}>1.335)=0.097[/tex]
And for this case the p value is higher than the significance level so then we FAIL to reject the null hypothesis and we can conclude that the true mean is at most 6 minutes
Step-by-step explanation:
Information given
[tex]\bar X=370.69/60 =6.178[/tex] represent the sample mean
[tex]s=24.36/36=0.68[/tex] represent the standard deviation for the sample
[tex]n=26[/tex] sample size
[tex]\mu_o =6[/tex] represent the value to verify
[tex]\alpha=0.05[/tex] represent the significance level
t would represent the statistic
[tex]p_v[/tex] represent the p value
System of hypothesis
We want to test if the true mean is at least 6 minutes, the system of hypothesis would be:
Null hypothesis:[tex]\mu \leq 6[/tex]
Alternative hypothesis:[tex]\mu > 6[/tex]
The statistic is given by:
[tex]t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}[/tex] (1)
Replacing the info we got:
[tex]t=\frac{6.178-6}{\frac{0.68}{\sqrt{26}}}=1.335[/tex]
The degrees of freedom are:
[tex]df=n-1=26-1=25[/tex]
The p value would be given by:
[tex]p_v =P(t_{25}>1.335)=0.097[/tex]
And for this case the p value is higher than the significance level so then we FAIL to reject the null hypothesis and we can conclude that the true mean is at most 6 minutes.
Solve the following inequality. |-2x + 1| < 13
Please help!!!!
Answer:
x>−6 and x<7
Step-by-step explanation:
Let's solve your inequality step-by-step.
|−2x+1|<13
Solve Absolute Value.
|−2x+1|<13
We know−2x+1<13and−2x+1>−13
−2x+1<13(Condition 1)
−2x+1−1<13−1(Subtract 1 from both sides)
−2x<12
−2x
−2
<
12
−2
(Divide both sides by -2)
x>−6
−2x+1>−13(Condition 2)
−2x+1−1>−13−1(Subtract 1 from both sides)
−2x>−14
−2x
−2
>
−14
−2
(Divide both sides by -2)
x<7
Answer:
x>−6 and x<7
2. Calculate the midpoint of the given
segment
|(-2, -3)
(0.1)
(2, 3)
Answer:0,1
Step-by-step explanation:
It’s on edge
An investigative bureau uses a laboratory method to match the lead in a bullet found at a crime scene with unexpended lead cartridges found in the possession of a suspect. The value of this evidence depends on the chance of a false positive positive that is the probability that the bureau finds a match given that the lead at the crime scene and the lead in the possession of the suspect are actually from two differant melts or sources. To estimate the false positive rate the bureau collected 1851 bullets that the agency was confident all came from differant melts. The using its established ctireria the bureau examined every possible pair of bullets and found 658 matches. Use this info to to compute the chance of a false positive.
Answer:
Step-by-step explanation:
Given that, we have 1851 bullets that we KNOW are NOT MATCHES of one another. One by one they examine two bullets at a time.
So, there are 1851 bullets but each time we choose 2.
We have, N choose K = N! / K! (N-k)!
Here, N = 1851 and K = 2
Therefore, 1851 choose 2 = 1851! / 2! (1851-2)!
= 1851! / 2! * 1849!
= 1712175 Possible Combinations
Out of these 653 are false positive.
The chance of getting false positive is = 658 / 1712175
= 0.000384
= 0.0384 %
Therefore, The correct option is
The chance of false positive is 0.0384% Because this probability is sufficiently small (< or = 1%) There is high confidence in the agency's forensic evidence.
The accompanying data represent the total travel tax (in dollars) for a 3-day business trip in 8 randomly selected cities A normal probability plot suggests the data could come from a population that is normally distributed. A boxplot indicates there are no outliers. Complete parts through below.
68.87 78.25 70.44 84.67 79.79 86.33 100.24 98.26
Click the icon to view the table of critical t-values.
a. Determine a point estimate for the population mean travel tax A point estimate for the population mean travel tax is $ 83.36. (Round to two decimal places as needed.)
b. Construct and interpret a 95% confidence interval for the mean tax paid for a three-day business trip.
Select the correct choice below and fill in the answer boxes to complete your choice. (Round to two decimal places as needed.)
A. The lower bound is $ and the upper bound is $. One can be % confident that all cities have a travel tax between these values.
B. The lower bound is $ and the upper bound is $ The travel tax is between these values for % of all cities.
C. The lower bound is $ and the upper bound is $ There is a % probability that the mean travel tax for all cities is between these values.
D. The lower bound is $ and the upper bound is One can be [95]% confident that the mean travel tax for all cities is between these values.
c. What would you recommend to a researcher who wants to increase the precision of the interval, but does not have access to additional data?
A. The researcher could decrease the level of confidence.
B. The researcher could decrease the sample standard deviation.
C. The researcher could increase the level of confidence.
D. The researcher could increase the sample mean
Answer:
Step-by-step explanation:
Given that:
68.87, 78.25, 70.44, 84.67, 79.79, 86.33, 100.24, 98.26
we calculate sample mean and standard deviation from given data
Sample Mean
[tex]\bar x = \frac{\sum (x)}{n} =\frac{666.85}{8} \\\\=83.35625[/tex]
Sample Variance
[tex]s^2= \frac{\sum (x- \bar x )^2}{n-1} \\\\=\frac{933.224787}{7} =133.317827[/tex]
sample standard deviation
[tex]s=\sqrt{s^2} \\=\sqrt{133.317827} \\ =11.546334[/tex]
95% CI for [tex]\mu[/tex] using t - dist
Sample mean = 83.35625
Sample standard deviation = 11.546334
Sample size = n = 8
Significance level = α = 1 - 0.95 = 0.05
Degrees of freedom for t - distribution
d-f = n - 1 = 7
Critical value
[tex]t_{\alpha 12, df}= t_{0.025, df=7}=2.365[/tex] ( from t - table , two tails, d.f =7)
Margin of Error
[tex]E = t_{\alpha 12, df}\times \frac{s_x}{\sqrt{n} } \\\\=2.365 \times \frac{11.546334}{\sqrt{8} } \\\\=2.365 \times 4.082246\\\\E=9.654512[/tex]
Limits of 95% Confidence Interval are given by:
Lower limit
[tex]\bar x - E = 83.35625-9.654512\\\\=73.701738\approx 73.702[/tex]
Upper Limit
[tex]= \bar x + E\\=83.35625+ 9.654512\\=93.010762 \approx 93.011[/tex]
95% Confidence interval is
[tex]\bar x \pm E = 83.35625 \pm 9.654512\\\\=(73.701738,93.010762)[/tex]
95% CI using t - dist (73.70 < μ < 93.01)
D. The lower bound is $ and the upper bound is One can be [95]% confident that the mean travel tax for all cities is between these values.
c.What would you recommend to a researcher who wants to increase the precision of the interval, but does not have access to additional data?
A. The researcher could decrease the level of confidence.
In the arcade game Skee Ball, players roll a ball up a ramp and receive 10 to 50 points based on where the ball lands. Players will attempt to aim the ball to receive higher scores, which are more difficult to achieve based on size and location. However, if a ball is rolled randomly up the ramp, the probabilities of the ball landing in different scoring areas are not equal. Assume the following probabilities for each possible score:
Score 10 Points 20 Points 30 Points 40 Points 50 Points
Probability 0.50 0.25 0.15 0.07 0.03
Assume that a player rolls three balls at random.
Required:
a. What is the probability of a total score of at least 100 points?
b. If the first ball scores 30 points, what is the probability of a total score of at least 100 points?
c. Are the events "the first ball scores 30" and the "total score is at least 100" independent? Why or why not??
d. What is the expected total score? What is the variance of the score on one roll?
Answer:
Step-by-step explanation:
a) sum of 100 can be achieved from following set of score
10,40,50. This score can be achieved in 3! ways
20,30,50. This score can be achieved in 3! ways
20,40,40. This score can be achieved in 4 ways
30,30,40. This score can be achieved in 4 ways
So,
P(score of 100)=
