Question

The 2015 American Time Use survey contains data on how many minutes of sleep per night each of 10,900 survey participants estimated they get. The times follow the Normal distribution with mean 529.9 minutes and standard deviation 135.6 minutes. An SRS of 100 of the participants has a mean time of ¯ x = 514.4 minutes. A second SRS of size 100 has mean ¯ x = 539.3 minutes. After many SRSs, the values of the sample mean ¯ x follow the Normal distribution with mean 529.9 minutes and standard deviation 13.56 minutes. What is the population?

A. The population is 135.6 million respondents to the American Time Use Survey.
B. The population is the 100 participants in the SRS.
C. The population is the 10,900 respondents to the American Time Use Survey.
D. The population is all Americans who sleep through the night.

Answer 1

The correct option is (D).

Explanation:

In statistics theory, population is a group of individuals from which a sample is collected to make inferences for this population. The sample collected is studied and various statistics are computed to estimate the population parameter value. For instance, mean, standard deviation, correlation.

In this case a sample of 10,900 Americans are selected and surveyed. The sample mean computed is used to estimate the population mean and the sample standard deviation is used to estimate the population standard deviation.

Thus, the population under study is all Americans who sleep through the night.

The correct option is (D).