Unit Test — Unit test Answers

The governor of Florida would like to estimate the mean age of all Florida residents. To do so, he randomly selects 500 Florida residents and determines their mean age to be 58.2 years. However, according the most recent census data, the mean age of all Florida residents is 55.6 years. Which of the following properly describes the 500 Florida residents who were randomly selected?

A bottled water company bottles varying sizes of water, from 8-ounce to 1-gallon containers. The company has determined that the mean quantity in their 20-ounce bottles is 20.8 ounces with a standard deviation of 0.6 ounces. The bottling plant manager believes his machines are overfilling the bottles. A random sample of 30 bottles is taken, and the mean number of ounces of water is determined to be 20.9. Under the assumption that the true mean ounces of water is 20.8, 100 simulated means for samples of size 30 are shown in the dotplot.Using the dotplot, is there evidence that machines are overfilling the 20-ounce bottles?

The salaries of professional baseball players are heavily skewed right with a mean of $3.2 million and a standard deviation of $2 million. The salaries of professional football players are also heavily skewed right with a mean of $1.9 million and a standard deviation of $1.5 million. A random sample of 40 baseball players’ salaries and 35 football players’ salaries is selected. The mean salary is determined for both samples. Let represent the difference in the mean salaries for baseball and football players. Which of the following represents the shape of the sampling distribution for ?

The daily temperatures for the winter months in Virginia are Normally distributed with a mean of 59°F and a standard deviation of 10°F. A random sample of 10 temperatures is taken from the winter months and the mean temperature is recorded. What is the standard deviation of the sampling distribution of the sample mean for all possible random samples of size 10 from this population?

A random sample of 100 cartons of eggs is selected from a grocery store, and it is discovered that 2% of the selected cartons contain at least one broken egg. A separate random sample of 100 cartons of eggs is selected from a club store and it is found that 5% of the selected cartons contain at least one broken egg. Which of the following statements is true?