In the modern era, tires last much longer than they used to. According to research, the life of tires has increased from
Posted: Thu May 05, 2022 8:18 pm
In the modern era, tires last much longer than they used
to. According to research, the life of tires has increased from
20,000 miles in 1970 to 80,000 miles in the recent decade. A
wholesaler wants to estimate the life of a Goodyear tire. He
examines a sample of 50 tires of the Goodyear brand and wants to
test whether or not the above is true. Assume that the wholesaler
tests these samples for their average life, and finds their average
life to be 75,000 miles, with a standard deviation of 8,000
miles.
a. At 95% confidence, determine if there is evidence that the
population mean is different from 75,000 miles.
to. According to research, the life of tires has increased from
20,000 miles in 1970 to 80,000 miles in the recent decade. A
wholesaler wants to estimate the life of a Goodyear tire. He
examines a sample of 50 tires of the Goodyear brand and wants to
test whether or not the above is true. Assume that the wholesaler
tests these samples for their average life, and finds their average
life to be 75,000 miles, with a standard deviation of 8,000
miles.
a. At 95% confidence, determine if there is evidence that the
population mean is different from 75,000 miles.