BADB 1014 final B Q3

a) An editor of a New York publishing company claims that the mean time taken to write a b) textbook is at least 31 months. A sample of 1B textbook authors found that the mean time taken by them to write a textbook was 25 months with a standard deviation of 7.2 months. Using a 2.5% signicance level. would you conclude that the editor's claim is true? Assume that the time taken to write a textbook is approximately normally distributed for all textbook authors. Answer the following questions. i. Identify the claim and state the Ho and H1. (1 Mark) ii. Find the critical value. (1 Mark) iii. Calculate the test statistic. (2 Marks) iv. Make a decision to reject or fail to reject Ho. (1 Mark) v. Interpret the decision in the context of the original claim. (1 Mark) A consulting agency was asked by a large insurance company to investigate if business majors were better salespersons than those with other majors. A sample of 20 salespersons with a business degree showed that they sold an average of 11 insurance policies per week. Another sample of 25 saiespersons with a degree other than business showed that they sold an average of 9 insurance policies per week. Assume that the two populations are approximately normally distributed with population standard deviations of 1.30 and 1.35 policies per week, respectively. Use a 1% signicance level to determine that persons with a business degree are better saiespersons than those who have a degree in another area. Answer the following questions. i. Identify the claim and state the Ho and H1. [1 Mark) ii. Find the critical value. (1 Mark) iii. Calculate the test statistic. (2 Marks) iv. Make a decision to reject or fail to reject Ho. (1 Mark) v. Interpret the decision in the context of the original claim. (1 Mark) The Pew Research Center conducted a poll in January 2014 of online adults who use social networking sites. According to this poil. 39% of the 18-29 year olds and 82% of the 3049 year olds who are online use social networking sites. Suppose that this survey included 562 online adults in the 16-29 age group and 624 in the 3049 age group. Using a 1% signicance levei. determine that 331 is different from 11:. Use both the critical-value and the p-vaiue approaches. Answer the following questions. i. Identify the claim and state the Ho and H1. (1 Mark) ii. Find the critical value. (1 Mark) iii. Calculate the test statistic. (2 Marks) iv. Calculate the p-value for the test. (2 Marks) v. Make a decision to reject or fail to reject Ho. (1 Mark) vi. interpret the decision in the context of the original claim. (1 Mark)