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A survey of investors finds that​ 60% use a full service brokerage firm to invest in​ stocks, 30% trade stocks online and​ 24% do both. What is the probability that an investor selected at random uses a full service brokerage firm or trades stocks​ online?

Which of the following is not an assumption​ and/or condition required for constructing a confidence interval for the​ proportion?

A researcher is conducting a study on Internet use. He decides to first categorize the population by education level​ (high school, college​ graduate, advanced​ degree, etc.) and then survey a select number from each category. What is this sampling strategy​ called?

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?  

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

An advocacy group is investigating whether gender has an effect on job category in large investment firms. She surveyed a sample of firms with the results shown in the following table. What is the probability that a randomly selected​ employee’s job category is executive​ / managerial given that she is​ female? Job Category Male Female Clerical​ / Technical 85 215 Professional Staff 720 480 Executive​ / Managerial 400 100

As an incentive to get new​ customers, the local branch of a bank launched​ “bouncing for​ bucks.” During this week long​ event, any customer opening a new checking account with the bank would have the opportunity to throw a bouncy rubber ball into a large box divided into squares. Each square was labeled with a dollar amount that would be deposited into​ his/her new checking account. The way the box was labeled is shown below. What is the probability that a customer does not get​ $50?

A consumer research group investigating the relationship between the price of meat (per pound) and the fat content (grams) gathered data that produced the following scatterplot. Which description of the association between fat content and price is more accurate?

A magazine that publishes product reviews conducted a survey of teenagers’ preferences for cell phones. Three brands of cell phone designed specifically with teens in mind were the focus of the study. The table summarizes responses by brand and gender. What percent of teenagers preferred LG Rumor?

5. Annual rings of a tree are composed of spring wood and summer wood. Spring wood is ____.