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. What is the best estimate of the average tread life in miles for the entire population of these tires?
A) 50,000
B) 3,500
C) (50,000/100)
D) (3,500/100)

Question

Quizplus · Accepted Answer

The best estimate of the average tread life in miles for the entire population of these tires is the sample mean, which is 50,000 miles. Choice A matches this reasoning. Choice B corresponds to the standard deviation, which is a measure of variability, not central tendency. Choice C is the sample mean divided by the sample size, which is already included in choice A. Choice D is the standard deviation divided by the sample size, which is not relevant for estimating the population mean.

Mileage Tests Were Conducted on a Randomly Selected Sample of 100