statistics homework 103

Chapter 7 Homework

1) Identify Whether to Use a One-tailed or Two-tailed Test Given H0: p ≥ 80% and Ha: p < 80%, determine whether the hypothesis test is left-tailed, right-tailed, or two-tailed.

2) A car maker claims that its new sub-compact car gets better than 47 miles per gallon on the highway. Determine whether the hypothesis test for this is left-tailed, right-tailed, or two-tailed.

3) The owner of a professional basketball team claims that the mean attendance at games is over 30,000 and therefore the team needs a new arena. Determine whether the hypothesis test for this claim is lefttailed, right-tailed, or two-tailed.

4) Interpret a Decision Based on the Results of a Statistical Test The mean age of bus drivers in Chicago is 50.2 years. If a hypothesis test is performed, how should you interpret a decision that rejects the null hypothesis?

5) The mean age of bus drivers in Chicago is greater than 57.8 years. If a hypothesis test is performed, how should you interpret a decision that rejects the null hypothesis?

6) The mean IQ of statistics teachers is greater than 160. If a hypothesis test is performed, how should you interpret a decision that rejects the null hypothesis?

7) Find the critical value for a right-tailed test with α = 0.01 and n = 75.

8) You wish to test the claim that μ ≠ 22 at a level of significance of α = 0.05 and are given sample statistics n = 35, x = 21.1, and s = 2.7. Compute the value of the standardized test statistic. Round your answer to two decimal places.

9) Find the standardized test statistic t for a sample with n = 15, x = 7.4, s = 0.8, and α = 0.05 if H0: μ ≤ 7.1. Round your answer to three decimal places.

10) Determine the critical value, z0, to test the claim about the population proportion p = 0.250 given n = 48 and p ^ = 0.231. Use α = 0.01.

11) Find the critical X2 -values to test the claim σ2 = 4.3 if n = 12 and α = 0.05.