OMS 301-The manufacturer of the X15 steel belted radial truck

1. The manufacturer of the X15 steel belted radial truck tire claims that the tires will get 60,000 miles before the tread wears out. This claim is made with a claimed standard deviation of 5000 miles. Just-In-Time trucking purchased 48 X-15 tires and found that the mean mileage of their tires was 59,000 miles. Was the tire manufacturer correct in their claim of an average of 60,000 miles for tread wear? Use the .10 level of significance.

2. According to a recent survey, Americans get an average of seven (7) hours of sleep each night. A random sample of 150 Davenport students revealed that the average amount of sleep for the students was 6 hours and 48 minutes (6.8 hours) with a standard deviation of .9 hours. From the data is it reasonable to conclude that the students at GVSU sleep less than the average American? Use the .05 level of significance.