1. Olympic gymnasts train an average of 36 hours per week. A random sample of 20 athletes was selected and it was found that the average practice per week was 38 hours.

Which of the following is a true statement about this scenario?

If a different random sample of 20 athletes were selected, the average practice per week in that sample would have to be also 38 hours.

Both 36 and 38 are parameters

Both 36 and 38 are statistics

36 is a parameter and 38 is a statistic.

The recorded sample average of 38 hours per week is clearly a mistake. It must be 36 hours per week just like the population mean.

2. Which of the following statements about the sampling distribution of the sample mean, x-bar, isnottrue?

The sampling distribution is normal regardless of the sample size, as long as the population distribution is normal.

The sampling distribution's mean is the same as the population mean.

The sampling distribution's standard deviation is smaller than the population standard deviation.

The sampling distribution is normal regardless of the shape of the population distribution, as long as the sample size, n, is small enough.

All of the above statements are true.

The next two questions refer to the following information:

To estimate the mean number of daily study hours in the population of all the students at a large public university, a researcher plans to randomly sample students from this population and then calculate the average number of daily study hours for the sample (x-bar). Pictured below (in scrambled order) are three histograms:

• The distribution of study hours in the population of all students in the university
• The sampling distribution x-bar when samples of size n=5 are chosen from the population.
• The sampling distribution x-bar when samples of size n=30 are chosen from the population.

\f