Answer:
Step-by-step explanation:
56.1
Answer:
h = -0.5
Step-by-step explanation:
110h + 115 = 63
63 - 115
= -52
110h = -52
h = -0.5
Answer:
The sample required is 
Step-by-step explanation:
From the question we are told that
The standard deviation is 
The margin of error is 
Given that the confidence level is 99% then the level of significance is mathematically evaluated as



Next we will obtain the critical value
from the normal distribution table(reference math dot armstrong dot edu) , the value is

The sample size is mathematically represented as
![n = [ \frac{Z_{\frac{\alpha }{2} } * \sigma }{E} ]^2](https://tex.z-dn.net/?f=n%20%3D%20%5B%20%5Cfrac%7BZ_%7B%5Cfrac%7B%5Calpha%20%7D%7B2%7D%20%7D%20%2A%20%20%5Csigma%20%7D%7BE%7D%20%5D%5E2)
substituting values
![n = [ \frac{ 2.58 * 9 }{2} ]^2](https://tex.z-dn.net/?f=n%20%3D%20%5B%20%5Cfrac%7B%202.58%20%2A%20%209%20%7D%7B2%7D%20%5D%5E2)

Answer:
For this case the confidence interval is given by :

Step-by-step explanation:
Data provided
represent the sample mean for the fuel efficiencies
population mean
s=2.51 represent the sample standard deviation
n=601 represent the sample size
Confidence interval
The formula for the confidence interval of the true mean is given by:
(1)
The degrees of freedom for this case is given by:
The Confidence level for this case is 0.95 or 95%, and the significance level
and
and the critical value is given by
Replcing into the formula for the confidence interval is given by:
For this case the confidence interval is given by :
