Answer:
The 99.5% confidence interval for the proportion of all shrubs of this species that will resprout after fire is (0, 0.5745).
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].
For this problem, we have that:
[tex]n = 18, \pi = \frac{5}{18} = 0.2778[/tex]
99.5% confidence level
So [tex]\alpha = 0.005[/tex], z is the value of Z that has a pvalue of [tex]1 - \frac{0.005}{2} = 0.9975[/tex], so [tex]Z = 2.81[/tex].
The lower limit of this interval is:
[tex]\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.2778 - 2.81\sqrt{\frac{0.2778*0.7222}{18}} = -0.01 = 0[/tex]
We cannot have a negative proportion, so we use 0.
The upper limit of this interval is:
[tex]\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.2778 + 2.81\sqrt{\frac{0.2778*0.7222}{18}} = 0.5745[/tex]
The 99.5% confidence interval for the proportion of all shrubs of this species that will resprout after fire is (0, 0.5745).
PLEASE HELP the inverse of the function graphed below is a function
True or false
Functions
Function NotationVertical Line Test
ApplicationStep 1: DefineLet's see what we are given.
We are given a graph of an inverse of a function.
Step 2: IdentifyWe need to figure out whether the graphed inverse function is a function or not.
By the definition of a function, we know that every x input must correlate with one y output. In layman's terms, each respective x input has its own specific y output.
This definition builds the foundation of the Vertical Line Test. We can use this simple "tool" to verify whether or not a given graph is a function or not.
By placing a vertical line "on" the graph, we can move it to determine whether an x input has only one y output.If a graph passes the Vertical Line Test, it is said to be a function.If a graph fails the Vertical Line Test, it is said to not be a function, but rather a relation, etc.Step 3: TestWhen we apply the Vertical Line Test to the graphed inverse function, we can see that every x input has only one specific y output.
∴ we can conclude that the graphed inverse function is indeed a function.
AnswerThe answer to the question would be A. True.
___
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___
Topic: Algebra I
Unit: Functions
A bag contains 7 red and 10 white balls. In how many ways 4 balls are selected if there are more than 2 red balls? (Please solve it using counting rule; combination rule.)
Answer:
385 ways
Step-by-step explanation:
Given;
7 red balls
10 white balls
In how many ways can 4 balls be selected if there are more than 2 red balls.
Selecting 4 balls which must contain more than 2 red balls, will be 3 red balls and 1 white ball to make it 4 in total, or all the 4 balls selected will red balls.
= 3 red balls and 1 white ball OR 4 red balls
= 7C₃ x 10C₁ + 7C₄
[tex]= \frac{7!}{4!3!} *\frac{10!}{9!1!} \ \ + \ \frac{7!}{3!4!} \\\\= (35*10) \ + \ 35\\\\= 350 \ + 35\\\\= 385 \ ways[/tex]
Therefore, there are 385 ways of selecting 4 balls, if there are more than 2 red balls.
3) Washing your hands kills germs. If there are 275 germs chilling on your hands and
you kill 4.75% per second of washing, how many germs left on your hands after 10
seconds. Round your answer to the nearest whole germ. (Remember, keep washing
those hands)
Answer:
So we can use geometric progression each time multiplying by 0.0475
so thats (275*0.0475)*10
So that means that we would get
130.625 so we subtract that from 275
275-130.625=144.375
That would be
Step-by-step explanation:
I NEED HELP PLEASE I have been on this question for a hour
Answer:
A-8
Step-by-step explanation:
Any other higher number plugged in makes the equation false
Quick Start Company makes a 12-volt car batteries. After many years of product testing, the company knows the average life of a Quick Start battery is normally distributed, with mean=45 months and a std. deviation = 8 months.
If Quick start guarantees a full refund on any battery that fails within the 36 month period after purchase, what percentage of its batteries will the company expect to replace?
If quick Start does not want to make refunds for more than 10% ofits batteries under the full refund guarantee policy, for how longshould the company guarantee the batteries (to the nearest month)
Answer:
The company will expect to replace 13.03% of batteries.
The company should guarantee the batteries for 35 months.
Step-by-step explanation:
Problems of normally distributed samples can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this question, we have that:
[tex]\mu = 45, \sigma = 8[/tex]
If Quick start guarantees a full refund on any battery that fails within the 36 month period after purchase, what percentage of its batteries will the company expect to replace?
This is the pvalue of Z when X = 36. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{36 - 45}{8}[/tex]
[tex]Z = -1.125[/tex]
[tex]Z = -1.125[/tex] has a pvalue of 0.1303.
The company will expect to replace 13.03% of batteries.
If quick Start does not want to make refunds for more than 10% ofits batteries under the full refund guarantee policy, for how longshould the company guarantee the batteries
They should guarantee to the 10th percentile, which is X when Z has a pvalue of 0.1. So it is X when Z = -1.28.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]-1.28 = \frac{X - 45}{8}[/tex]
[tex]X - 45 = -1.28*8[/tex]
[tex]X = 34.76[/tex]
Rounding to the nearest month
The company should guarantee the batteries for 35 months.
The lines shown below are perpendicular if the green line has a slope of 3/4 what is the slopes of the red line?
Answer:
b) -4/3
Step-by-step explanation:
perpendicular lines have slopes that are opposite reciprocals. the opposite of 3/4 is -3/4, and the reciprocal of -3/4 is -4/3. hope this helps!
Answer:
It is -4/3
Step-by-step explanation:
The U.S. Department of Housing and Urban Development publishes data on the fair market monthly rent for existing one-bedroom housing by metropolitan area (The Federal Register, April 30 1997). The standard deviation for the monthly rent is about $80. Assume that a sample of metropolitan areas will be selected in order to estimate the population mean of the monthly rent for existing one-bedroom housing. Use 95% confidence. a. How large should the sample be if the desired margin of error is $25?
Answer:
[tex]n=(\frac{1.960(80)}{25})^2 =246.73 \approx 247[/tex]
So the answer for this case would be n=247 rounded up to the nearest integer
Step-by-step explanation:
We know that the standard deviation is :
[tex]\sigma = 80[/tex] represent the deviation
The margin of error is given by this formula:
[tex] ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}[/tex] (a)
And on this case we have that ME =25 and we are interested in order to find the value of n, if we solve n from equation (a) we got:
[tex]n=(\frac{z_{\alpha/2} \sigma}{ME})^2[/tex] (b)
The critical value for 95% of confidence interval now can be founded using the normal distribution and the critical value would be [tex]z_{\alpha/2}=1.960[/tex], replacing into formula (b) we got:
[tex]n=(\frac{1.960(80)}{25})^2 =246.73 \approx 247[/tex]
So the answer for this case would be n=247 rounded up to the nearest integer
Calculate the surface area of the egg (in μm2). The formula for calculating the surface area (SA) of a sphere is given below. SA = 4Ïr2. Use 3.14 as the value for Ï.
Answer:
[tex]31400\mu m^2[/tex]
Step-by-step explanation:
We are given that
Diameter of egg,d=[tex]100\mu m[/tex]
We have to find the surface area of egg in [tex]\mu m^2[/tex].
Radius of egg,r=[tex]\frac{d}{2}=\frac{100}{2}=50\mu m[/tex]
Surface area of sphere=[tex]4\pi r^2[/tex]
Where [tex]\pi=3.14[/tex]
Using the formula
Surface area of egg=[tex]4\times 3.14(50)^2[/tex]
Surface area of egg=[tex]31400\mu m^2[/tex]
Hence, the surface area of the egg=[tex]31400\mu m^2[/tex]
Plz help. Dora calculated the mean absolute deviation for the data set 35, 16, 23, 42, and 19. Her work is shown below. Step 1: Find the mean. mean = StartFraction 35 + 16 + 23 + 42 + 19 Over 5 EndFraction = 27 Step 2: Find each absolute deviation. 8, 11, 4, 15, 8 Step 3: Find the mean absolute deviation. M A D = StartFraction 8 + 11 + 4 + 15 Over 5 EndFraction = 9.5 What is Dora’s error?
A. Dora should have divided by 4 when finding the mean
B. Dora found the absolute deviation of 35 incorrectly
C. Dora used only four numbers in finding the mean
D. Dora used only four numbers in finding the mean absolute deviation
Answer:
step 3 is wrong
Step-by-step explanation:
i know it because i did the unit test review
Answer:
D
ヾ(•ω•`)o
Step-by-step explanation:
Really in need of help :( please !
Answer:
A
Step-by-step explanation:
(2,1) - only one in the table. Remember (x,y)
Classify the triangle by its sides, and then by its angles.
60 degrees
60 degrees
60 degrees
4 ft
4 ft
4 ft
Classified by its sides, the triangle is a(n)
▼
equilateral
scalene
isosceles
triangle.
Classified by its angles, the triangle is a(n)
▼
obtuse
acute
right
triangle.
Answer:
Equilateral, acute
Step-by-step explanation:
Equilateral triangles have all sides the same length (all sides are 4 ft in this triangle, so it is equilateral).
Acute triangles have no angles that are greater than or equal to 90 degrees (all angles are 60, which is less than 90, so it is acute).
Write down the definition of a random sample.
Answer:
Step-by-step explanation:
Random sampling is a procedure for sampling from a population in which (a) the selection of a sample unit is based on chance and (b) every element of the population has a known, non-zero probability of being selected.
Answer:
A simple random sample is a subset of a statistical population in which each member of the subset has an equal probability of being chosen.
I hope this helped...
Lily paints 3 trees for a wall mural. The middle tree is 2 1/2 ft tall. The tree on the left is 3/4 as tall as the middle tree. The tree on the right is 1 3/4 times as tall as the middle tree. How tall is each tree?
Answer:
middle is 2.5 ft
right is 4375 ft
left is 1875 ft
Step-by-step explanation:
Gia is painting her wall. 1 liter of paint can cover 10 square metres. She has a rectangular wall that measures 4 metres by 5 meters. How many liters of paint will Gia need to cover her wall?
Answer:
2 liters of paint.
Step-by-step explanation:
First we nned to know to total area of the wall by using the formula A = lw
A = 4*5 = 20m²
then we given 1 liter cover 10 m², 20 m² = 2 liters of paint.
3 of 6
As an estimation we are told £3 is €4.
Convert £85.40 to euros.
Give your answer rounded to 2 DP
Answer:
€113.67
Step-by-step explanation:
£3 = €4
£85.40 is €x
Cross multiply.
[tex]4 \times 85.4=3x[/tex]
[tex]3x=341.6[/tex]
[tex]\frac{3x}{3}=\frac{341.6}{3}[/tex]
[tex]x=113.86666...[/tex]
An intravenous fluid is infused at the rate shown in the table. What is the missing value?
Minutes
Milliliters
3
ܢܚܪ
2.
?
3
9
4
12
3
6
9
24
Answer:
the answer is 6!!!!!!
Step-by-step explanation:
The missing value in the table is 5
What is Slope of Line?The slope of the line is the ratio of the rise to the run, or rise divided by the run. It describes the steepness of line in the coordinate plane.
The slope intercept form of a line is y=mx+b, where m is slope and b is the y intercept.
The slope of line passing through two points (x₁, y₁) and (x₂, y₂) is
m=y₂-y₁/x₂-x₁
An intravenous fluid is infused at the rate shown in the table
Minutes Milliliters
3 4
? 12
2. 3
? 6
3 9
9 24
Slope=24-9/9-3
=15/3
=5
Now 5=12-4/x-3
5=8/x-3
5x-15=8
5x=23
x=23/5
x=4.6
x=5
The missing number is 5.
Hence, the missing value in the table is 5
To learn more on slope of line click:
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x/2 = -5 solve for x
Answer:
[tex]x=-10[/tex]
Step-by-step explanation:
[tex]\frac{x}{2}=-5\\\mathrm{Multiply\:both\:sides\:by\:}2\\\frac{2x}{2}=2\left(-5\right)\\Simplify\\x=-10[/tex]
pls help it due tomorrow
Answer:
Finding 1/5 of something is the same as dividing that number by 5. Since 24 isn't divisible by 5, 24 / 5 is not an integer. Since you can't have 4.8 species of animals the answer to (a) is no.
For (b), 1/3 * 24 = 8 and 24 - 8 = 16.
Angle EFB is 108º
a)Find the size of angle x.
b) which one of these justifies your answer?
A-corresponding angles
B- Alternate angles
C- vertically opposite angles
Answer:
c of what im sure about
Step-by-step explanation:
A cereal box has a volume of 225 cubic inches. The length of the base is 9 inches and the width of the base is
2.5 inches. What is the height of the box?
Answer:
10
Step-by-step explanation:
First multiply 9 by 2.5
Then divide 225 by 22.5
The table shows the daily sales (in $1000) of shopping mall for some randomly selected days Sales 1.1-1.5 1.6-2.0 2.1-2.5 2.6-3.0 3.1-3.5 3.6-4.0 4.1-4.5 Days 18 27 31 40 56 55 23 Use it to answer questions 13 and 14. 13. What is the approximate value for the modal daily sales? A. $3,129.41 B. $2,629.41 C. $3,079.41 14. The approximate median daily sales is ... A. $3,130.36 B. $2,680.36 C. $3,180.36 D. $3,123.53 D. $2,664.29
Answer:
Step-by-step explanation:
From the question; we are given the following inclusive frequency distribution information
Class Frequency f
1.1-1.5 18
1.6-2.0 27
2.1-2.5 31
2.6-3.0 40
3.1-3.5 56
3.6-4.0 55
4.1-4.5 23
Convert the above inclusive frequency distribution to exclusive frequency distribution with respect of the upper and lower class limit ; we have:
Class Frequency f
1.05 - 1.55 18
1.55 - 2.05 27
2.05 - 2.55 31
2.55 - 3.05 40
3.05 - 3.55 56
3.55 - 4.05 55
4.05 - 4.55 23
Class Frequency f cf
1.05 - 1.55 18 18
1.55 - 2.05 27 45
2.05 - 2.55 31 76
2.55 - 3.05 40 116
3.05 - 3.55 56 172
3.55 - 4.05 55 227
4.05 - 4.55 23 250
n = 250
To determine the daily sales; we can derive that from estimated Mode by using the relation :
Estimated Mode = L + fm − fm-1(fm − fm-1) + (fm − fm+1) × w
here:
L = the lower class boundary of the modal group
fm-1 = the frequency of the group before the modal group
fm = the frequency of the modal group
fm+1 = the frequency of the group after the modal group
w = the group width
However;
It is easier now to determine the modal group (i.e the group with the highest frequency), which is 3.05 -3.55
L = 3.05
fm-1 =40
fm =56
fm+1 = 55
w = 0.5
∴[tex]mode = 3.05 + \dfrac{56 - 40 }{(56 - 40) + (56 -55)} * 0.5 \\ \\ mode = 3.05 + 0.4705 \\ \\ mode = 3.5205[/tex]
To find Median Class ; we use the formula;
Median Class = value of (n / 2)th observation
Median Class = value of (250 / 2)th observation
Median Class = value of 125th observation
From the column of cumulative frequency cf,
we will see that the 125th observation lies in the class 3.05-3.55.
∴ The median class is 3.05-3.55.
Thus;,
L=lower boundary point of median class =3.05
n=Total frequency =250
cf=Cumulative frequency of the class preceding the median class =116
f=Frequency of the median class =56
c=class length of median class =0.5
[tex]Median M=L+n2-cff- c \\ \\ =3.05+125-11656⋅0.5 \\ \\=3.05+0.08036 \\ \\ =3.13036[/tex]
hence median sales = $3130.36
Help me which answer is it
Answer:
C.
Step-by-step explanation:
[tex]\frac{1}{5} +\frac{5}{6}[/tex] ≈ 1
5 + 8 + 1 = 14
2. Students who wish to represent the school at a school board meeting are asked to stop
by the office after lunch. After lunch, 5 students wish to represent the school.
Answer: Biased sample
Step-by-step explanation:
This is a biased sample because only students with strong opinions are likely going to volunteer or show interest in representing the school at the board meeting. This sample is a voluntary type sample, and at such the conclusion is not valid. This sample is biased because a group or population of students have a higher or lower sampling probability.
What is the equation of the line perpendicular to y = 2/3x+1that passes through the point (12, -6)?
Answer:[tex]y=-\frac{3}{2} x+12[/tex]
Step-by-step explanation:
Perpendicular lines have inversely proportional slopes. So make the slope negative and switch it to its reciprocal.
2/3x would change into -3/2x
Lets write that down for a starting point for our perpendicular line.
y = -3/2x + b
We were given the x and y value via the coords. x = 12 and y = -6
Now we have -6 = -3/2(12) + b. Multiply -3 and 12 to get -36, then divide by 2 to get -18. Now it's -6 = -18 + b. Solve for b by adding 18 to both sides to get b = 12
The weekly salaries of sociologists in the United States are normally distributed and have a known population standard deviation of 425 dollars and an unknown population mean. A random sample of 22 sociologists is taken and gives a sample mean of 1520 dollars.
Find the margin of error for the confidence interval for the population mean with a 98% confidence level.
z0.10 z0.05 z0.025 z0.01 z0.005
1.282 1.645 1.960 2.326 2.576
You may use a calculator or the common z values above. Round the final answer to two decimal places.
Answer:
[tex] ME =z_{\alpha/2} \frac{\sigma}{\sqrt{n}}[/tex]
The confidence level is 0.98 and the significance is [tex]\alpha=1-0.98 =0.02[/tex] and [tex]\alpha/2 =0.01[/tex] and the critical value using the table is:
[tex]z_{\alpha/2}= 2.326[/tex]
And replacing we got:
[tex] ME=2.326 \frac{425}{\sqrt{22}}= 210.760\ approx 210.76[/tex]
Step-by-step explanation:
For this case we have the following info given:
[tex]\sigma = 425[/tex] represent the population deviation
[tex] n =22[/tex] the sample size
[tex]\bar X =1520[/tex] represent the sample mean
We want to find the margin of error for the confidence interval for the population mean and we know that is given by:
[tex] ME =z_{\alpha/2} \frac{\sigma}{\sqrt{n}}[/tex]
The confidence level is 0.98 and the significance is [tex]\alpha=1-0.98 =0.02[/tex] and [tex]\alpha/2 =0.01[/tex] and the critical value using the table is:
[tex]z_{\alpha/2}= 2.326[/tex]
And replacing we got:
[tex] ME=2.326 \frac{425}{\sqrt{22}}= 210.760\ approx 210.76[/tex]
A four-year study of various brands of bottled water found that 25% of bottled water is just tap water packaged in a bottle. Consider a sample of sevenseven bottled-water brands, and let x equal the number of these brands that use tap water. Complete parts a through d.
a. Is x (approximately) a binomial random variable?
b. Give the probability distribution for x as a formula.
c. Find p(x = 2).
d. Find P(x <= 1).
Answer:
Answers below
Step-by-step explanation:
a. Is x (approximately) a binomial random variable?
b. Give the probability distribution for x as a formula.
c. Find p(x = 2).
d. Find P(x <= 1).
What is the greatest number of right angles a triangle can contain?
A. 0
B. 1
C. 3
D. 2
The answer is B..........
Answer:
B. 1
Step-by-step explanation:
If it was more than one it wouldn't be a triangle.
According to a report released by CIBC entitled "Women Entrepreneurs: Leading the Charge," the average age for Canadian businesswomen in 2008 was 41. In the report, there was some indication that researchers believed that this mean age will increase. Suppose now, a few years later, business researchers in Canada want to test to determine if, indeed, the mean age of Canadian businesswomen has increased. The researchers randomly sample 97 Canadian businesswomen and ascertain that the sample mean age is 43.4. From past experience, it is known that the population standard deviation is 8.95. Test to determine if the mean age of Canadian businesswomen has increased using a 1% level of significance. What is the p-value for this test? What is the decision? If the null hypothesis is rejected, is the result substantive?
Answer:
We conclude that the mean age of Canadian businesswomen has increased.
Step-by-step explanation:
We are given that according to a report released by CIBC entitled "Women Entrepreneurs: Leading the Charge," the average age for Canadian businesswomen in 2008 was 41.
The researchers randomly sample 97 Canadian businesswomen and ascertain that the sample mean age is 43.4. From past experience, it is known that the population standard deviation is 8.95.
Let [tex]\mu[/tex] = mean age of Canadian businesswomen.
So, Null Hypothesis, [tex]H_0[/tex] : [tex]\mu[/tex] [tex]\leq[/tex] 41 {means that the mean age of Canadian businesswomen has decreased or remained same}
Alternate Hypothesis, [tex]H_A[/tex] : [tex]\mu[/tex] > 41 {means that the mean age of Canadian businesswomen has increased}
The test statistics that would be used here One-sample z-test statistics because we know about population standard deviation;
T.S. = [tex]\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }[/tex] ~ N(0,1)
where, [tex]\bar X[/tex] = sample mean age of Canadian businesswomen = 43.4
[tex]\sigma[/tex] = population standard deviation = 8.95
n = sample of Canadian businesswomen = 97
So, the test statistics = [tex]\frac{43.4-41}{\frac{8.95}{\sqrt{97} } }[/tex]
= 2.64
The value of z test statistic is 2.64.
Also, P-value of the test statistics is given by;
P-value = P(Z > 2.64) = 1 - P(Z < 2.64)
= 1 - 0.99585 = 0.00415
Now, at 1% significance level the z table gives critical value of 2.33 for right-tailed test.
Since our test statistic is more than the critical value of z as 2.64 > 2.33, so we have sufficient evidence to reject our null hypothesis as it will fall in the rejection region due to which we reject our null hypothesis.
Therefore, we conclude that the mean age of Canadian businesswomen has increased.
7+2x/3=5 im stuck on this question pls hhelp my homework is due soon pls help
The value of X is 4
please see the attached picture for full solution
Hope it helps
Good luck on your assignment..
find the area enclosed by the curve y^2=x^2-x^4
Answer: 4/3
Step-by-step explanation:
As you know this graph is a lemniscate
[tex]4\int\limits^1_0 {x\sqrt{1-x^{2} } \, dx =\frac{4}{3} =1.33$[/tex]