Describe how the width of a​ 95% confidence interval for a mean changes as the standard deviation​(s​) of a sample​ increases, assuming sample size remains the same.

Top management of a large multinational corporation wants to create a culture of innovativeness and change. A consultant hired to assess the​ company’s organizational culture finds that only​ 15% of employees are open to new ideas and approaches toward their work. Consequently the company conducts a program for employees in order to reinforce the new corporate philosophy. After the program is​ completed, employees are surveyed to see if a greater percentage is now open to innovativeness and change. What is the correct alternative​ hypothesis?

Which of the following is NOT an assumption or condition that needs to be checked for a paired t​-​interval?

Business decisions should always take into consideration which of the​ following? I. The statistical significance of the test II. The cost of the proposed action III. The effect size

Suppose that the time for e-mail confirmation of an online order is uniformly distributed between 1 and 6 minutes. The probability that an email confirmation arrives within 3 minutes is 

Which is true about a​ 99% confidence interval based on a given​ sample? I. The interval contains​ 99% of the population. II. Results from​ 99% of all samples will lie in this interval. III. The interval is wider than a​ 95% confidence interval would be.

A researcher is conducting a study on eating disorders. Using a list of recent participants in the online Weight Watchers​ program, she randomly selects a sample from the alphabetized list. What does this list​ represent?  

A researcher is conducting a study to determine how knowledgeable teenagers are about making good food choices. She decides to interview teenagers eating at a fast food restaurant. The results may be biased because this is what type of​ sample?

An advocacy group is investigating whether gender has an effect on job category in large investment firms. Given the results shown in the table​ below, which of the following statements is true about gender and job​ category? Job Category Male Female Clerical​ / Technical 85 215 Professional Staff 720 480 Executive​ / Managerial 400 100

Suncast Cable offers high definition​ (HD) cable​ TV, Internet and phone services to its customers. For those service issues that can be resolved by calling its technical support​ center, Suncast’s goal is to have the problem solved within 30 minutes. In order to determine how well it is achieving this​ goal, they monitored calls to its technical support center over the last three months. The data compiled is shown in the table below. What is the probability that a call to the technical support center involved an issue with Internet service or was not resolved within 30​ minutes? Problem Resolved? HD cable TV Internet Phone Yes 123 350 77 No 115 122 63