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One-Sample Hypothesis Nancy believes that the average running time of movies is

ID: 3321853 • Letter: O

Question

One-Sample Hypothesis

Nancy believes that the average running time of movies is equal to 140 minutes. A sample of 4 movies was taken and the following running times were obtained. 150 150 180 170

Answer the following:

a. Assume you are trying to determine if the sample of movies taken differs from Nancy’s assumption. Determine if the appropriate hypothesis test should be an upper tail, lower tail, or 2-tail test.

b. Determine the value of the test statistic.

c. Determine the critical z or t value using a level of significance of 10%.

d. Determine the p-value.

e. State your conclusion: Reject Ho or Do not Reject Ho? (Using a significance level of 10%).

f. Could a Type II error have been committed?

Please no rounding.

Explanation / Answer

(a) It is a 2-tail test

(b)

SE = s/n = 15/4 = 7.5

t = (x-bar - )/SE = (162.5 - 140)/7.5 = 3

(c)

Degrees of freedom = 4 - 1 = 3

Lower Critical t- score = -2.353363435

Upper Critical t- score = 2.353363435

(d)  p- value = 0.057668886   

(e) Since 3 > 2.353363 we reject Ho and accept Ha

(f) Yes