Exam 8: Sampling Variability and Sampling Distributions

A statistic is a characteristic of the population.

What is a sampling distribution of a statistic?

Suppose we artificially categorize populations as approximately normal or not, and samples as large or small.This categorization results in 4 categories: a)Small samples from an approximately normal population b)Large samples from an approximately normal population c)Small samples from a population that is not approximately normal d)Large samples from a population that is not approximately normal

The sampling distribution of p tends to be more spread out for larger sample sizes than for smaller sample sizes.

According to internal testing done by the Get-A-Grip tire company, the mean lifetime of tires sold on new cars is 23,000 miles, with a standard deviation of 2500 miles. c)If the distribution of tire life is approximately normal, what is the probability that the mean of a random sample of size n = 4 of tire lifetimes will be less than 20,000 miles?