The salaries of professional baseball players are heavily skewed right with a mean of [tex]$\$[/tex]3.2[tex]$ million and a standard deviation of $[/tex]\[tex]$2$[/tex] million. The salaries of professional football players are also heavily skewed right with a mean of [tex]$\$[/tex]1.9[tex]$ million and a standard deviation of $[/tex]\[tex]$1.5$[/tex] 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 [tex]$\bar{x}_B - \bar{x}_F$[/tex] represent the difference in the mean salaries for baseball and football players.

Which of the following represents the shape of the sampling distribution for [tex]$\bar{x}_B - \bar{x}_F$[/tex]?

A. Skewed right since the populations are both right-skewed.
B. Skewed right since the differences in salaries cannot be negative.
C. Approximately Normal since both sample sizes are greater than 30.
D. Approximately Normal since the sum of the sample sizes is greater than 30.



Answer :

To determine the shape of the sampling distribution for the difference in the mean salaries ([tex]$\bar{x}_B - \bar{x}_F$[/tex]) of professional baseball and football players, we need to recall the Central Limit Theorem (CLT). The CLT states that when the sample size is sufficiently large (typically [tex]$n > 30$[/tex]), the sampling distribution of the sample mean can be modeled by a Normal distribution regardless of the population distribution’s shape.

Given:
- The sample size for baseball players is 40.
- The sample size for football players is 35.

Both of these sample sizes are greater than 30, hence large enough to apply the Central Limit Theorem.

### Step-by-Step Solution

1. Analyze the Population Distributions:
- The salaries for baseball and football players are heavily skewed right.
- Even though individual populations are skewed, we are looking at the sampling distribution of the sample means.

2. Central Limit Theorem Application:
- Baseball Players: With a sample size of 40, the sampling distribution of the mean salary of baseball players is approximately Normal.
- Football Players: With a sample size of 35, the sampling distribution of the mean salary of football players is approximately Normal.

3. Difference of Means Distribution:
- The difference in sample means [tex]$\bar{x}_B - \bar{x}_F$[/tex] will also follow a Normal distribution since both sampling distributions are approximately Normal.

Therefore, based on the Central Limit Theorem and the given sample sizes, the shape of the sampling distribution for [tex]$\bar{x}_B - \bar{x}_F$[/tex] is approximately Normal. Hence:

### Final Answer:
Approximately Normal since both sample sizes are greater than 30.