Homework Problem 13.21 and 13.41 Goodness-of-Fit and Contingency Analysis

 Skill Development13-21.A marketing research firm is conducting a study to determine if there is a relationshipbetween an individual’s age and the individual’s preferred source of news. The research firmasked 1,000 individuals to list their preferred source for news: newspaper, radio and television,or the Internet (Groebner, Shannon, & Fry, 2014). 

 At the 0.01 level of significance, can the marketing research firm conclude that there is arelationship between the age of the individual and the individual’s preferred source for news(Groebner, Shannon, & Fry, 2014)?SolutionX2= 300. 531 > 16.8119, reject the null hypothesisBusiness Application13-41.Cooper Manufacturing, Inc., of Dallas, Texas, has a contract with the U.S. Air Force toproduce a part for a new fighter plane being manufactured. The part is a bolt that hasspecifications requiring that the length be normally distributed with a mean of 3.05 inches and astandard deviation of 0.015 inch. As part of the company’s quality-control efforts, each dayCooper’s engineers select a random sample of 100 bolts produced that day and carefully measurethe bolts to determine whether the production is within specifications. The following data werecollected yesterday (Groebner, Shannon, & Fry, 2014):