Question

1. You work for a consumer watchdog publication and are testing the advertising claims of a tire manufacturer. The manufacturer claims that the life spans of the tires are normally distributed, with a mean of 40,000 miles and a st deviation of 7500 miles. You test 16 tires and get the following life spans. Complete parts (a) through (c) below. 47,006 42,352 25,758 35,706 32,631 40,540 42,475 37,466 25,752 30,020 35,387 36,646 30,709 36,082 35,930 44,177 (a) Draw a frequency histogram to display these data. Use five classes. Choose the correct answer below. O A Ов. Ос. Life spans of tires Life spans of tires Life spans of tires 27,877 44,881 27,877 44,881 27,877 44,881 Distance (ia miles) Distance (in miles Distance in miles) Is it reasonable to assume that the life spans are normally distributed? Why? Choose the correct answer below O A. No, because the histogram is symmetric and bell-shaped. 0 B. Yes, because the histogram is neither symmetric nor bell-shaped. O C. No, because the histogram is neither symmetric nor bell-shaped O D. Yes, because the histogram is symmetric and bell-shaped. (b) Find the mean of your sample. The mean is Round to one decimal place as needed.) Find the standard deviation of your sample. The standard deviation is . (Round to one decimal place as needed.) (c) Compare the mean and standard deviation of your sample with those in the manufacturers claim. Discuss differences. Choose the correct answer below. O A. The sample mean is less than the claimed mean, so, on average, the tires in the sample lasted for a shorter time. The sample standard deviation is less than the claimed standard deviation, so the tires in the sample had a smaller variation in life span. The sample mean is less than the claimed mean, so, on average, the tires in the sample lasted for a shorter time. The sample standard deviation is greater than the claimed standard deviation, so the tires in the sample had a greater variation in life span. The sample mean is greater than the claimed mean, so, on average, the tires in the sample lasted for a longer time. The sample standard deviation is greater than the claimed standard deviation, so the tires in the sample had a greater variation in life span. O B. ° C.

Answer 1

AnsGes dak eguene HAS 2500 о- 2 3ok- 35k 3 2 45k - 50k malgel than the claimes mean Go, on auhoge the tes n the Samm denahen,So thehe sample hade smaler