Sampling Distributions
a. Many different samples of size 100 are randomly selected from the weights of cars currently registered in the United States. What can be concluded about the shape of the distribution of the means of the different samples?
b. If the weights of all cars registered in the United States have a standard deviation of 512 lb, what is the standard deviation of the sample means that are found from many different samples of size 100?
c. Many different samples of size 1200 are randomly selected from the population of all adults in the United States. In each sample, the proportion of people who voted in the last election is recorded. What can be concluded about the shape of the dis- tribution of those sample proportions?