Answer:
Step-by-step explanation:
Simple regression was employed to establish the effects of childhood exposure to lead. THe effective sample size was about 122 subjects. THe independent variable was the level of dentin lead (parts per million). Below are regressions using various dependent variables.
Calculate the t statistic for each slope, at significance level = 0.01.
Dependent Variable R2 Estimated Std. t calculated p-value Differ from 0?
Slope Error
Highest grade achieved .061 −0.027 0.009 .008 No / Yes
Reading grade equivalent .121 −0.070 0.018 .000 No / Yes
Class standing .039 −0.006 0.003 .048 No / Yes
Absence from school .071 4.8 1.7 .006 No / Yes
Grammatical reasoning .051 0.159 0.062 .012 Yes / No
Vocabulary .108 −0.124 0.032 .000 No / Yes
Hand-eye coordination .043 0.041 0.018 .020 No / Yes
Reaction time .025 11.8 6.66 .080 No / Yes
Minor antisocial behavior .025 −0.639 0.36 .082 Yes / No
B) It would be inappropriate to assume cause and effect without a better understanding of how the study was conducted.
1. No
2. Yes
solution[tex]t=\frac{\text {estimated slope}}{\text {std error}}[/tex]
a)
Estimated Slope Std error t - calculated
-0.027 0.009 -3
-0.070 0.018 -3.89
-0.006 0.003 -2
4.8 1.7 2.82
0.159 0.062 2.56
-0.124 0.032 -3.87
0.041 0.018 2.28
11.8 6.66 1.77
-0.639 0.36 -1.78
b) Yes, It would be inappropriate to assume cause and effect without a better understanding of how the study was conducted.
ASAP! GIVING BRAINLIEST! Please read the question THEN answer CORRECTLY! NO guessing. I say no guessing because people usually guess on my questions.
Answer:
6x^2 -2x -6
Step-by-step explanation:
f(x) = 6x^2 -4
g(x) = 2x+2
f(x) - g(x) = 6x^2 -4 - (2x+2)
Distribute the minus sign
6x^2 -4 - 2x-2
Combine like terms
6x^2 -2x -6
Answer:
b
Step-by-step explanation:
6x^2
2x
-4+2=-2
Find the area of the trapezoid to the nearest tenth.
Answer:
2.2 metres squared
Step-by-step explanation:
We need to find the area of this trapezoid.
The area of a trapezoid is denoted by:
[tex]A=\frac{(b_1+b_2)h}{2}[/tex], where [tex]b_1[/tex] and [tex]b_2[/tex] are the parallel bases and h is the height
Here, we already know the lengths of the two bases; they are 0.9 metres and 2.3 metres. However, we need to find the length of the height.
Notice that one of the angles is marked 45 degrees. Let's draw a perpendicular line from top endpoint of the segment labelled 0.9 to the side labelled 2.3. We now have a 45-45-90 triangle with hypotenuse 2.0 metres. As one of such a triangle's properties, we can divide 2.0 by √2 to get the length of both legs:
2.0 ÷ √2 = √2 ≈ 1.414 ≈ 1.4
Thus, the height is h = 1.4 metres. Now plug all these values we know into the equation to find the area:
[tex]A=\frac{(b_1+b_2)h}{2}[/tex]
[tex]A=\frac{(0.9+2.3)*1.4}{2}=2.2[/tex]
The answer is thus 2.2 metres squared.
~ an aesthetics lover
A charity receives 2025 contributions. Contributions are assumed to be mutually independent and identically distributed with mean 3125 and standard deviation 250. Calculate the approximate 90th percentile for the distribution of the total contributions
Answer:
The 90th percentile for the distribution of the total contributions is $6,342,525.
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
Normal probability distribution
Problems of normally distributed samples are 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.
Central Limit Theorem
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
For sums of size n, the mean is [tex]\mu*n[/tex] and the standard deviation is [tex]s = \sqrt{n}*\sigma[/tex]
In this question:
[tex]n = 2025, \mu = 3125*2025 = 6328125, \sigma = \sqrt{2025}*250 = 11250[/tex]
The 90th percentile for the distribution of the total contributions
This is X when Z has a pvalue of 0.9. So it is X when Z = 1.28. Then
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]1.28 = \frac{X - 6328125}{11250}[/tex]
[tex]X - 6328125 = 1.28*11250[/tex]
[tex]X = 6342525[/tex]
The 90th percentile for the distribution of the total contributions is $6,342,525.
James notes the angle of elevation of the top of tower to be 30 degree if James is 100meter away horizontally from the base of the tower find the height of the tower?
Answer:
Around 57.74 feet
Step-by-step explanation:
The tower and James form a right triangle, where the other two angles are 30 degrees and 60 degrees. The tangent of an angle is equivalent to the length of the opposite side divided by the length of the adjacent side, which means:
[tex]\tan 30=\dfrac{x}{100} \\\\x=\tan 30 \cdot 100 \approx 57.74[/tex]
Hope this helps!
??!!!?!?
.....
....
...
Answer:
A) (3,2)
Step-by-step explanation:
Conditions:
x+y ≤ 6x ≥ 0y ≥ 0A) (3,2)
yes, as all 3 conditions are met3+2≤6, 3≥0, 2≥0B) (0,7)
no, as the first condition is not met0+7 > 6sum what is the sum of 199+ -24=
?
Answer:
175
Step-by-step explanation:
+ × - = -
thus 199+(-24)
199-24
175
Answer: 199 + -24 = 175
Step-by-step explanation: 199 is a positive number and -24 is a negative number. If the positive number is bigger than the negative number you subtract. So forget that the - sign is there and subtract it.
Alex needs
80
cm
80 cm80, start text, space, c, m, end text of thread for a sewing project. The thread is on a spool with a circumference of
10
cm
10 cm10, start text, space, c, m, end text.
How many times must Alex unwind the spool to get the length of thread he needs?
Answer:
8 full turns
Step-by-step explanation:
80 cm is 8 times 10 cm, so is 8 times around the spool.
Alex must unwind 8 full turns of thread from the spool.
__
He must unwind it once.
Answer:
8 in total turns
Step-by-step explanation:
4. In the Department of Natural Sciences, 14 faculty members have a PhD, and 30 faculty
members do not have a PhD. In the Department, the number of female faculty who do not
have a PhD is 10 more than the number of females who have a PhD. If a third of the male
faculty in the Department have a PhD, then what is the number of female faculty in the
Answer:
8
Step-by-step explanation:
We can start by making the table below to show the given numbers (red) and to assign a variable (x) to the number we want to find: female PhDs.
By subtracting the female numbers from the totals, we can find the corresponding numbers of male PhDs and non-PhDs.
The number of male non-PhDs is twice the number of male PhDs, so we have ...
2(14 -x) = 20 -x
28 -2x = 20 -x . . . . eliminate parentheses
8 = x . . . . . . . . . . . .add 2x-20
The number of female faculty with PhDs is 8.
A design engineer wants to construct a sample mean chart for controlling the service life of a halogen headlamp his company produces. He knows from numerous previous samples that when this service life is in control it is normally distributed with a mean of 500 hours and a standard deviation of 20 hours. On three recent production batches, he tested service life on random samples of four headlamps, with these results: Sample Service Life (hours) 1 495 500 505 500 2 525 515 505 515 3 470 480 460 470 What is the mean of the sampling distribution of sample means when the service life is in control
Answer:
[tex]$ \text {Sample mean} = \bar{x} = \mu = 500 \: hours $[/tex]
Step-by-step explanation:
What is Normal Distribution?
We are given a Normal Distribution, which is a continuous probability distribution and is symmetrical around the mean. The shape of this distribution is like a bell curve and most of the data is clustered around the mean. The area under this bell shaped curve represents the probability.
For the given scenario, it is known from numerous previous samples that when this service life is in control it is normally distributed with a mean of 500 hours and a standard deviation of 20 hours.
On three recent production batches, he tested service life on random samples of four headlamps.
We are asked to find the mean of the sampling distribution of sample means when the service life is in control.
Since we know that the population is normally distributed and a random sample is taken from the population then the mean of the sampling distribution of sample means would be equal to the population mean that is 500 hours.
[tex]$ \text {Sample mean} = \bar{x} = \mu = 500 \: hours $[/tex]
Whereas the standard deviation of the sampling distribution of sample means would be
[tex]\text {standard deviation} = s = \frac{\sigma}{\sqrt{n} } \\\\[/tex]
Where n is the sample size and σ is the population standard deviation.
[tex]\text {standard deviation} = s = \frac{20}{\sqrt{4} } \\\\ \text {standard deviation} = s = \frac{20}{2 } \\\\ \text {standard deviation} = s = 10 \: hours \\\\[/tex]
What is the slope of the line?
Benjamin deposits $3,000 into each of two savings
accounts. The first savings account pays 5% interest
compounded annually. The second savings account
pays 5% simple interest annually. If Benjamin makes
no other deposits or withdrawals, what will be the
difference between the interest earned by the two
savings accounts after 4 years?
Answer:
So I have never stepped foot into this. But I have experience from this. So for the first one we can use the compound intrest formula - A = P(1+r/n)^nt so if we do that we get.
A = 3000(1+0.05/1)^1*4
So then we get A is equal to 3646.52
The next one we need to calculate
A = P (1 + rt)
So now we do A = 3000(1+0.05*1)
A = 3000*1.05 = 3150. We add them together and we get 6796.52.
So we subtract 6000 from that. He earned
796.52 dollars
A researcher wants to test the claim that convicted burglars spend an average of 18.7 months in jail. She takes a random sample of 11 such cases from court files and finds x=20.6 months and s=8 months. Test the claim that u=18.7 months at the 0.05 significance level.
Answer:
[tex]t=\frac{20.6-18.7}{\frac{8}{\sqrt{11}}}=0.788[/tex]
The degrees of freedom are given by;
[tex] df =n-1= 11-1=10[/tex]
And the p value would be:
[tex]p_v =2*P(t_{10}>0.788)=0.449[/tex]
Since the p value is higher than the significance level we have enough evidence to FAIL to reject the null hypothesis and we can conclude that the true mean is not significantly different than 18.7
Step-by-step explanation:
Information given
[tex]\bar X=20.6[/tex] represent the sample mean
[tex]s=8[/tex] represent the sample standard deviation
[tex]n=11[/tex] sample size
[tex]\mu_o =18.7[/tex] represent the value to test
[tex]\alpha=0.05[/tex] represent the significance level
t would represent the statistic
[tex]p_v[/tex] represent the p value
Hypotesis to test
We want to verify if the true mean is equal to 18.7, the system of hypothesis would be:
Null hypothesis:[tex]\mu =18.7[/tex]
Alternative hypothesis:[tex]\mu \neq 18.7[/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{20.6-18.7}{\frac{8}{\sqrt{11}}}=0.788[/tex]
The degrees of freedom are given by;
[tex] df =n-1= 11-1=10[/tex]
And the p value would be:
[tex]p_v =2*P(t_{10}>0.788)=0.449[/tex]
Since the p value is higher than the significance level we have enough evidence to FAIL to reject the null hypothesis and we can conclude that the true mean is not significantly different than 18.7
What’s the correct answer for this question?
Answer:
A.
Step-by-step explanation:
A quadrilateral inscribed in a circle has its opposite angles adding up to 180°
So
<NOP + <M = 180
4x+8x-24 = 180
12x = 180+24
12x = 204
Dividing both sides by 12
x = 17
<NOP = 4(17)
= 68°
Find the volume of the prism.
The volume is cubic meters.
Determine whether the following procedure is a binomial experiment.
If it is not, explain why. Drawing 5 marbles from a bag with 10 red, 8 green and 12 yellow marbles without replacement and finding out how many of these five are green.
a. Yes, this is a binomial experiment.
b. No, the outcomes cannot be classified into two categories.
c. No, the trials are not independent
Answer:
C. The trails are not independent.
The probability of drawing one marble will not be independent of others thus option (c) is correct.
What is probability?The probability of an event occurring is defined by probability.
Probability is also called chance because if you flip a coin then the probability of coming head and tail is nothing but chances that either head will appear or not.
As per the given,
Drawing 5 marbles from a bag with 10 red, 8 green, and 12 yellow marbles without replacement.
In without replacement, the remaining balls in each draw will go to be decreased thus they will be dependent events so binomial distribution will not be applied.
Hence "One marble's likelihood of being drawn won't be independent of the other marbles".
For more information about the probability,
brainly.com/question/11234923
#SPJ5
Two students, A and B, are working independently on homework (not necessarily for the same class). Student A takes X = Exp(1) hours to finish his or her homework, while B takes Y = Exp(2) hours. (a) Find the CDF of X/Y , the ratio of their problem-solving times. (b) Find the probability that A finishes his or her homework before B does.
Answer:
a) The CDF of X/Y is calculated as:
[tex]F_{z} (\zeta) = \frac{\zeta}{\zeta + 2}[/tex] for [tex]0 < \zeta < \infty[/tex]
[tex]F_{z} (\zeta) = 0[/tex] for [tex]\zeta \leq 0[/tex]
Note: Z = X/Y
b) Probability that A finishes before B = 1/3
Step-by-step explanation:
For clarity and easiness of expression, this solution is handwritten and attached as a file. Check the complete solution in the attached file.
6(x/2 + 4) greater than or equal to 9
Answer:
Greater than 9.
Step-by-step explanation:
[tex]6(x/2 + 4)[/tex]
[tex]3x+24[/tex]
F(x)=2x-6 and g(x)=3x+9,find (f+g)(x)
Answer: 5x-3
Step-by-step explanation:
(f+g)(x) means f(x)+g(x). Knowing this, we add the 2 functions together.
2x-6+3x+9
5x-3
A system of equations has 1 solution. If 4x - y = 5 is one of the equations, which could be the other equation?
O y=-4x + 5
y = 4x-5
2y = 8x - 10
-2y = -8x - 10
Answer:
[tex]4x -y = 5[/tex]
And if we rewrite this expression we got:
[tex] y= 4x -5[/tex]
If the system have just one solution then we need the slope different and for this reason we can discard the options:
y = 4x-5
-2y = -8x - 10 equivalent to y =4x+5
2y = 8x - 10 equivalent to y = 4x -5
And then the correct answer would be:
y=-4x + 5
Step-by-step explanation:
For this case we have the following equation given:
[tex]4x -y = 5[/tex]
And if we rewrite this expression we got:
[tex] y= 4x -5[/tex]
If the system have just one solution then we need the slope different and for this reason we can discard the options:
y = 4x-5
-2y = -8x - 10 equivalent to y =4x+5
2y = 8x - 10 equivalent to y = 4x -5
And then the correct answer would be:
y=-4x + 5
Answer:
A: y = –4x + 5
Step-by-step explanation:
I got it right on Edge
Find the value of x for which the figure below is a parallelogram
Answer:
x = 2
Step-by-step explanation:
Well the diagonals bisect each other.
4x = 8
x = 2
Answer:
x = 2
Step-by-step explanation:
5x = 3x+4
2x = 4
x = 2
what is the solution? X - 7 > -6
Answer:
x > 1
Step-by-step explanation:
Add 7 to both sides
x > 1
use the graph of y = tan x to find the value of y = tan 0. round to the nearest tenth of necessary. if the tangent is undefined at that point, write undefined.
a. 0.4
b. 0
c. -0.4
d. 1
Step-by-step explanation:
The graph of y = tan x is shown. We need to find what y equals when x = 0 (because in y = tan 0, x is replaced with 0)
So you can either find where x = 0 on the graph, or you can take the tangent of 0 to find your answer.
The value of the trigonometric function [tex]y = \tan x[/tex] at (x = 0) is 0 and this can be determined by using the given graph.
Given :
The graph of [tex]y = \tan x[/tex].
The following steps can be used to determine the value of [tex]y = \tan 0[/tex] :
Step 1 - The graph of the trigonometric function [tex]y = \tan x[/tex] is given.
Step 2 - According to the given graph, at (x = 0) the value of y is also 0.
Step 3 - So, the value of the trigonometric function [tex]y = \tan x[/tex] at (x = 0) is:
[tex]y = \tan 0[/tex]
[tex]y = 0[/tex]
The value of the trigonometric function [tex]y = \tan x[/tex] at (x = 0) is 0.
For more information, refer to the link given below:
https://brainly.com/question/14375099
Which ordered pair is the best estimate for the
solution of the system of equations?
y =
3x + 6
y = 1x – 2
Answer:
-4, -6
Step-by-step explanation:
3x+6= 1x-2
2x+6= -2
2x= -8
x= -4
Now that you have your x variable, you can go back and plug it in to your original equations:
y= 3(-4)+6,
y= (-12)+6 therefore y= -6
y=1(-4) -2,
y= (-4) -2 therefore y = -6
A square of area 36cm2 is cut to make two rectangles, A and B The ratio of Area A to Area B is 2 : 1 Work out the dimensions of rectangle A and B
(Need help with this question)
Answer:
Given..hope it helps
Step-by-step explanation:
Area of square= 36cm2 = total area
Side of square= √36= 6cm
Ratio a:b = 2:1
so let's take total area as 3x
while a is 2x and b is 1x
3x= 36 (given)
x= 36/3 = 12
so area of each rectangle--
area A= 2x= 24cm2
area B= x= 12cm2
While finding the dimensions, they both have a common length since they are from the same square which will be 6cm (side)
So,
Dimensions of rectangle A= 6cm * 4cm
Dimensions of rectangle B= 6cm * 2cm
please help you will get 20 points and explain your answer please
Answer:
Top prism = 262 in.² Bottom prism = 478 in.²
Step-by-step explanation:
top prism:
front + back: 5 x 3 = 15
sides: 19 x 4 x 2 = 152
bottom: 19 x 5 = 95
15 + 152 + 95 = 262
bottom prism:
front + back: 5 x 6 x 2 = 60
sides: 19 x 6 x 2 = 228
top + bottom: 19 x 5 x 2 = 190
60 + 228 + 190 = 478
Answer:
Top prism = 262 in.² Bottom prism = 478 in.²
Step-by-step explanation:
top prism:
front + back: 5 x 3 = 15
sides: 19 x 4 x 2 = 152
bottom: 19 x 5 = 95
15 + 152 + 95 = 262
bottom prism:
front + back: 5 x 6 x 2 = 60
sides: 19 x 6 x 2 = 228
top + bottom: 19 x 5 x 2 = 190
60 + 228 + 190 = 478
Solve -3(2x - 9) = -3.
Answer:
X=4
Step-by-step explanation:
1. Distribute 3 to 2x and -9
2. You will get "6x-27 = -3"
3. Next, add 27 to -27 and -3
4. You will get "6x = 24"
5. Then, you will divide 6x and 24 by 6
6. You will get "6x/6 = 24/6"
7. The 6 will cancel the 6 in 6x.
8. Then, you will divide 24 and 6. which will give you the answer of 4
9. Add the "X=..." and...
10. You will get the answer of "X=4"
Determine whether the sampling method is independent or dependent. A stock analyst wants to know if there is a difference between the mean rate of return from energy stocks and that from financial stocks. He randomly selects 13 energy stocks and computes the rate of return for the past year.
Answer:
The sampling method is independent.
Step-by-step explanation:
Samples are said to be dependent when the data chosen in one sample has an effect on the data to be chosen in the other sample, while samples are said to be independent if the data chosen in one sample has no effect on the data to be chosen on the other sample.
Here, the stock analyst wants to know if there is a difference between the mean rate of return from energy stocks and that from financial stocks, so, he randomly selects 13 energy stocks. Since the energy stocks he chose were randomly selected, it means the data he selected from the energy stock will not dictate the type of data to be selected from the financial stock. Thus, the sampling method is said to be independent.
evaluate the formula of A=lw, for l=10.8 cm and w=2.5 cm
Answer:
A = 27 cm²
Step-by-step explanation:
[tex]A = lw\\Where, l=10.8 cm , w = 2.5 cm\\[/tex]
Putting in the above formula
A = (10.8)(2.5)
A = 27 cm²
11+11=4, 22+22=16, 33+33?
Sequence= 4, 16
Difference=12
16+12=28
Answer is...
33+33=28
A company determines that monthly sales S(t), in thousands of dollars, after t months of marketing a product is given by S(t)equals2 t cubed minus 45 t squared plus 180 t plus 130. a) Find Upper S prime(1), Upper S prime(2), and Upper S prime(4). b) Find Upper S double prime(1), Upper S double prime(2), and Upper S double prime(4). c) Interpret the meaning of your answers to parts (a) and (b).
Answer: a) S'(1) = 136; S'(2) = 104; S'(4) = 76;
b) S''(1) = -38; S''(2) = -26; S''(4) = -2
Step-by-step explanation:
a) S' means first derivative;
[tex]\frac{d}{dt}[/tex](6t³ - 45t² +180t +130) = 6t² - 50t + 180
S'(1) = 6.1² - 50.1 + 180
S'(1) = 136
S'(2) = 6.2² - 50.2 + 180
S'(2) = 104
S'(4) = 6.4² - 50.4 + 180
S'(4) = 76
b) S'' is the second derivative of S:
[tex]\frac{d^2}{dt^2}[/tex](6t² - 50t + 180) = 12t - 50
S''(1) = 12.1 - 50
S''(1) = -38
S''(2) = 12.2 - 50
S"(2) = -26
S"(4) = 12.6 - 50
S"(4) = -2
c) Derivative is the rate of change of a function. The first derivative is the slope of the tangent line to the graph if the function in a determined point, while the second derivative measures how the rate of change is changing.
Analysing the values, we can conclude that the sales of the product after t months is decreasing at a rate of 12.
