On all of them sorry but if i dont know wich one to do then....
(a) 404 subjects are needed to estimate the mean HDL cholesterol within 2 points with 99% confidence.
(b) When the confidence level decreases to 95%, the number of subjects decreases from 404 to 234.
<u>Explanation:</u>
Given:
σ = 15.6
Let the number of subjects be n
(a)
When the confidence level is 99%, then z = 2.576
E = 2
We know:
![n = [\frac{z X s}{E}]^2](https://tex.z-dn.net/?f=n%20%3D%20%5B%5Cfrac%7Bz%20X%20s%7D%7BE%7D%5D%5E2)
On substituting the value, we get:
![n = [\frac{2.576 X 15.6}{2} ]^2\\\\n = 403.7](https://tex.z-dn.net/?f=n%20%3D%20%5B%5Cfrac%7B2.576%20X%2015.6%7D%7B2%7D%20%5D%5E2%5C%5C%5C%5Cn%20%3D%20403.7)
Thus, 404 subjects are needed to estimate the mean HDL cholesterol within 2 points with 99% confidence.
(b)
When the confidence level is 95%, then z = 1.96
E = 2
We know:
![n = [\frac{z X s}{E}]^2](https://tex.z-dn.net/?f=n%20%3D%20%5B%5Cfrac%7Bz%20X%20s%7D%7BE%7D%5D%5E2)
On substituting the value, we get:
![n = [\frac{1.96 X 15.6}{2} ]^2\\\\n = 233.7](https://tex.z-dn.net/?f=n%20%3D%20%5B%5Cfrac%7B1.96%20X%2015.6%7D%7B2%7D%20%5D%5E2%5C%5C%5C%5Cn%20%3D%20233.7)
n = 234
Thus, when the confidence level decreases to 95%, the number of subjects decreases from 404 to 234.
Answer:
The y-intercept is [0, 4].
Step-by-step explanation:
The y-intercept is the point at which where the line intersects the y-axis.
I am joyous to assist you anytime.
First translate the question into an equation.
"What percent" means x/100, "of 40" means times 40, "is 14" equals 14.
So we have (x)(40) = 14 or 40x = 14.
Dividing both sides by 40, we find that x = 0.35.
Now, we want to write our answer as a percent.
So we move the decimal 2 places to the right and we have 35%.