# (solution) For the numerical questions below, express your answers in four

For the numerical questions below, express your answers in four decimal places.

Past experience indicates that average download times of an online newspaper via a browser on mobiles is normally distributed with a mean of 0.92 seconds and a population standard deviation of 0.74 seconds. After an advertising campaign aimed at showing the benefits of a new nationwide 4G network, the manager of a telecommunications firm took a random sample of 24 customers and recorded their average download times. The manager found the sample average to be 0.67 seconds. The manager is looking to conduct a statistical test at the 10% level of significance to determine whether the campaign lowered mean download times.

Part A) What is the null hypothesis?

H0: ? ? 0.92H0: ? < 0.92H0: ? = 0.67H0: ? ? 0.67H0: X?? 0.92

Part B) What is the alternate hypothesis?

H1: ? < 0.92H1: ? ? 0.92H1: ? ? 0.67H0: ? < 0.67H0: X?< 0.92

Part C) What is the value of ??

Part D) What is the sampling distribution of the sample mean?

The sampling distribution is normal since the population standard deviation is known.The sampling distribution is a student-t since the population standard deviation is known.There is not enough information to answer this question.

Part E) What is the value of the test statistic? 