Answer:
D. 0.71 miles
Step-by-step explanation:
1250 ÷ 1760 = 0.71
Answer:
0.09 OR 9% is her tax
Step-by-step explanation:
Deborah has to pay 9% for tax. So is someone worked on her computer for two hours then she pays 9% on $120 worth of work. So her tax amount would be $10.800 and her total amount would be 10.8 +120 = $130.80.
(9 x² + 8 x + 2) - ( 4 x² + 2 x -5 )
= 9 x² + 8 x + 2 - 4 x² - 2 x + 5
= 5 x² + 6 x + 7
(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.