Question

Mileage tests were conducted on a randomly selected sample of 100 newly developed automobile tires. The average tread wear was found to be 50,000 miles with a standard deviation of 3,500 miles. With only the information provided, what is the best estimate of the average tread life in miles for the entire population of these tires

Answer 1

50,000 miles

Explanation:

- The best estimation of population mean would be to determine the sample mean. Since the sample size of n = 100 is large enough ( > 30 ).

- The population mean can be reasonably estimated to be equal to sample mean. This condition holds true or reasonably accurate when sample size is large ( > 30 ).

- Otherwise, if n < 30, then we would have to make an unbiased point estimation for the population mean by using the sample mean.

Hence, the answer is 50,000 miles of tread wear.