Exercise 9.37 THE VIDEO GAME SATISFACTION RATING CASE

Recall that "very satisfied" customers give the XYZ-Box video game system a rating that is at least 42. Suppose that the manufacturer of the XYZ-Box wishes to use the random sample of 65 satisfaction ratings to provide evidence supporting the claim that the mean composite satisfaction rating for the XYZ-Box exceeds 42.

Required:

(a)

Letting represent the mean composite satisfaction rating for the XYZ-Box, set up the null hypothesis H₀ and the alternative hypothesis H_a needed if we wish to attempt to provide evidence supporting the claim that exceeds 42.

H₀: __________ 42 versus H_a: __________ 42.

(b)

The random sample of 65 satisfaction ratings yields a sample mean of x = 42.954. Assuming that equals 2.64, use critical values to test H₀ versus H_a at each of = .10, .05, .01, and .001. (Round your answer to z_.05 to 3 decimal places and other z-scores to 2 decimal places.)

z = ____________

Rejection points

z_.10

____________

z_.05

____________

z_.01

____________

z_.001

____________

Reject H₀ with = __________ , but not with =__________ .

(c)

How much evidence is there that the mean composite satisfaction rating exceeds 42?

There is __________ evidence.