What is the value of the test statistic z Give your answer t

What is the value of the test statistic z?
Give your answer to 3 decimal places.
Fill in the blank:

1. Exercise 14.19 (page 365) describes a class survey in which students claimed to study an average of =118 minutes on a typical weeknight. standard deviation ? = 65. Regard these students as an SRS from the population of all first-year students at this university. Does the study give good evidence that students claim to study less than 2 hours per night on the average?

Solution

(A)D.

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(B)test statistic:

Z=(xbar-mu)/(s/vn)

=(118-120)/(65/sqrt(463))

=-0.662

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(C) It is a left-tailed test.

So the p-value= P(Z<-0.662) =0.2540 (from standard normal table)

Answer: A.Larger than 0.05.

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(D)C .We do not reject the null hypothesis and conclude the average student studies about 2 hours per night.