# Question

The number of cell phone users has increased dramatically since 1987. According to the Semi-annual Wireless Survey, published by the Cellular Telecommunications & Internet Association, the mean local monthly bill for cell phone users in the United States was $49.94 in 2007. A hypothesis test is to be performed to determine whether last year’s mean local monthly bill for cell phone users has decreased from the 2007 mean of $49.94.

a. Determine the null hypothesis.

b. Determine the alternative hypothesis.

c. Classify the hypothesis test as two tailed, left tailed, or right tailed.

a. Determine the null hypothesis.

b. Determine the alternative hypothesis.

c. Classify the hypothesis test as two tailed, left tailed, or right tailed.

## Answer to relevant Questions

Suppose that, in a hypothesis test, the null hypothesis is in fact true. a. Is it possible to make a Type I error? Explain your answer. b. Is it possible to make a Type II error? Explain your answer. Refer to Exercise 9.6. Explain what each of the following would mean. a. Type I error b. Type II error c. Correct decision Now suppose that the results of carrying out the hypothesis test lead to rejection of the null ...Refer to Exercise 9.13. Explain what each of the following would mean. a. Type I error b. Type II error c. Correct decision Now suppose that the results of carrying out the hypothesis test lead to nonrejection of the null ...a. Rejection region. b. Nonrejection region. c. Critical value(s). d. Significance level. e. Construct a graph similar to that in Fig 9.2 on page 350 that depicts your results from parts (a)–(d). f. Identify the hypothesis ...A two-tailed test with α = 0.05. Determine the critical value(s) for a one-mean z-test. For each exercise, draw a graph that illustrates your answer.Post your question

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