Exam 8: Hypothesis Testing

Alyson Silvastein, a scientist, reports that the average number of hours a person can go without sleep and still function normally is 29 with a standard deviation of five hours. A sample of 49 people had an average of 31 hours that they could go without sleep and still function normally. The test value for this hypothesis would be 2.8.

The critical value for a right-tailed test with α = 0.03 is 1.88.

If the null hypothesis is rejected at 0.05 when a mean of 15.0 is obtained from a random sample, one could also say that

Are the following statements and valid null and alternative hypotheses?

Use the following to answer questions: A recent survey indicated that the average amount spent for breakfast by business managers was $7.58 with a standard deviation of $0.42. It was felt that breakfasts on the West Coast were higher than $7.58. A sample of 81 business managers on the West Coast had an average breakfast cost of $7.65. -At α = 0.05, what is the critical value?

A type II error occurs if one does not reject the null hypothesis when it is __________.

When a researcher fails to reject the null hypothesis, this does not mean that there is not enough evidence to support the ________________.

Are the following statements and a valid pair of null and alternative hypothesis?

A recent study of business travelers claims they spend an average of $41.00 per day on meals. As a test of this claim, a random sampling of 16 business travelers found they had spent an average of $45.00 per day with a standard deviation of $3.65. What are the critical values for a two-tailed t test of this claim with α = 0.05?

At a certain university, the average attendance at basketball games has been 2925. This year the attendance for the first 11 games has been 2715 with a standard deviation of 535. The athletic director claims that the attendance is the same as last year. If = .05, what are the critical values for this two-tailed t test?

If the null hypothesis is not rejected at 0.01 when a mean of 7.0 is obtained from a random sample, one could also say that

For the conjecture "The average rent of an apartment is more than $900 per month," the alternative hypothesis is:

For the conjecture "The average age of students in this class is 20", the null hypothesis is:

Reginald Brown, an inspector from the Department of Weights and Measures, weighed 15 eighteen-ounce cereal boxes of corn flakes. He found their mean weight to be 17.8 ounces with a standard deviation of 0.4 ounces. At α = 0.01, are the cereal boxes lighter than they should be?

Nationwide, the average waiting time until a electric utility customer service representative answers a call is 210 seconds. The Gigantic Kilowatt Energy Company randomly sampled 30 calls and found that, on average, they were answered in 183 seconds with a population standard deviation of 30 seconds. Can the company claim that they are faster than the average utility at α = 0.05?

Using Table G, find the P-value interval for the test value. , n = 11, right-tailed

The power of a test measures the sensitivity of the test to detect a real difference in parameters if one actually exists.

An average department store sells 150 men's suits per year. The men's suit departments at a particular national chain of stores claim they sell more than the industry average. In 45 of their stores, they sold, on the average, 190 suits per year with a population standard deviation of 30. What is the test value for their claim?

A type I error occurs if one rejects the null hypothesis when it is __________.

A right-tailed test is used when .