Exam 8: Hypothesis Testing

Balance disturbances can be a common source of difficulty for senior citizens. One type of balance test involves standing on one leg, arms crossed and eyes open. The population mean for females, aged 60 - 69, on the balance test is 30 seconds with a σ = 5 seconds. A fitness instructor is implementing a program at her facility, which she calls "Toe the Line," designed to improve balancing skills. After completing the program, a sample of 15 females in the 60 - 69 age group take the balance test. The mean for the sample was M = 32. Using a one-tailed z-test and α = .05, determine whether the program improved balancing skills in older females.

Explain what is meant by the power of a statistical test. What are the factors that increase power?

If there is a difference between the population mean and our obtained sample mean, the alternative hypothesis states that the difference is due to

If we make a Type I error, then we have

Explain why obtained sample values that fall in the critical region of a sampling distribution result in rejection of the null hypothesis.

In statistical terminology, the term "significant" in the results section

Which of the following is not one of the assumptions for the z-test?

Is it easier to reject a null hypothesis with a one-tailed test or a two-tailed test? Explain.

If the mean of a population is 10, which of the following is not a correctly stated null hypothesis for a z-test?

If the results of a hypothesis test include the phrase "p > .05," then the decision should be made to ____________.

Which of the following alpha levels would have the greatest risk of a Type II error?

Using Jacob Cohen's guidelines for interpreting the size of an effect, d = .74 would indicate

If there were serious consequences of making a Type I error, which alpha level would you choose?

The population mean of a standardized test on Cheerfulness is 50. An attitude coach who conducts self-improvement workshops administered the test to a sample of his participants. The obtained sample mean was 55. Since the obtained sample mean was 5 points higher than the population mean can we, therefore, conclude that the workshop was effective? Why or why not?