Use Excel or Megastat to: 1. Construct a 95% confidence interval for the populat
ID: 3183716 • Letter: U
Question
Use Excel or Megastat to: 1. Construct a 95% confidence interval for the population mean miles per gallon consumption for passenger cars. 2. Test the hypothesis that the population mean miles per gallon gasoline consumption for passenger cars is different from 25 mpg. Use a significance level of 5% a) Do we know a for the mpg consumption? Can we use the normal distribution for the hypothesis test? b) State the null and alternative hypotheses. c) Perform the appropriate test and print the output. d Look at the P-value in the output. Compare it to a. Do we reject the null hypothesis or not? e) Generate the descriptive statistics for the data.Explanation / Answer
Answers below with formula:
1. 95% CI is given by :
Mean +/- SE*Z
=26.86 +/- .99*1.96
=24.92 to 28.80
A. Yes we know sigma. Yes we can use normal dist for test
B.
Ho: Mu=25
Ha: Mu!=25
C. Z = (26.86-25)/7.33 = .254
D. alpha=.05, pvalue for Z=.254 = .60
Since alpha < pvalue of .6 we do not reject null hypothesis.
Conclusion: Mu=25
E. This step has already been performed by you in the pic