The dataset NFLContracts 2015 contains the yearly salary (in millions of dollars) from the contracts of all players on a National Football League (NFL) roster at the start of the 2015 season. 

(a) Use StatKey or other technology to select a random sample of 5 NFL contract Yearly-Salary values. Indicate which players you've selected and compute the sample mean.

(b) Repeat part (a) by taking a second sample of 5 values, again indicating which players you selected and computing the sample mean.

(c) Find the mean for the entire population of players. Include notation for this mean. Comment on the accuracy of using the sample means found in parts (a) and (b) to estimate the population mean.