A. Compute the mean and the standard deviation of the above sample
data.
Be sure to find the appropriate standard deviation for purposes of carrying out the hypothesis test of interest.
a. Sample Mean =Round to 1 decimal place please
a. Sample Standard Deviation =
Round to 4 decimal places please.
B. Use the above sample data to find a 95% confidence interval
for the population mean number of months a fuel injection system lasts before it needs replacement.
The 95% confidence interval for mean number of months a fuel injection system lasts before it needs replacement is
a. (_,_) Round to 3 decimal places please
C. State the null and alternate hypotheses that would be used to test the consumer group's suspicion that the fuel injection system lasts less than 48 months before it needs to be replaced
H0: μ < 48="" versus h1:="" μ="" ="">
H0: μ = 48 Versus H1: μ <>
H0: μ = 48 Versus H1: μ ≠ 48
H0: μ = 48 Versus H1: μ > 48
D. Continuing part (c), find the p-value of the appropriate test and decide whether or not to reject the null hypothesis at the 5% significance level.
a. P-value =
Round to 4 decimal places.
b. Based on 5% level of significance, your final conclusion is:
Reject the null hypothesis OR
Fail to reject the null hypothesis
E.
Does the manufacturer’s claim appear to be plausible? That is, did you find sufficient sample evidence to support the manufacturer’s claim?
a. YES, There is a significant evidence that the fuel injection system lasts at least 48 months before it needs to be replaced
b. NO, There is NO significant evidence that the fuel injection system lasts at least 48 months before it needs to be replaced
F. What type of error is possible with your final decision about the null hypothesis in part (d).