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# Confidence interval for mean

A random sample of 172 students was asked to rate on a scale to from 1 (not important) to 5 (extremely important) health benefits as a job characteristic (note that the rating scale can also have decimals, i.e. a student can give a rating of 1.32). The sample mean rating was 3.31, and the sample standard deviation was 0.70.

A.
1) Obtain a 95% confidence interval for the mean rating.
2) Explain what the interval represents.

B)
1)For a type I error of 1%, can you be reasonably certain that the average rating is more than 3 in the population?

2) State the hypothesis verbally

3) State the hypothesis symbolically

4) Briefly explain the testing procedure
a) What type of test you to use
b) How to calculate the test statistic
c) How to calculate the p-value and the rejection criteria.

C)
1) Obtain a 99% confidence interval for the mean rating.
2) Can you use the 99% confidence interval to test the hypothesis from part b? Why or why not?

D)
What assumption(s) are needed in order answer the above questions?

#### Solution Summary

This solution gives the step by step method for computing confidence interval

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