A company has many salespersons working in many sales regions. The volume of sales generated by each person was calculated for the first day in September. The standard deviation of the western sales staff was $83. The standard deviation for the eastern sales staff was $64. A sample of 25 eastern staff had a mean of $550. A sample of 30 western was $590. What is the probability of observing these sample means if the population means are the same?

0.0488
0.0244
0.1970
0.043
PLEASE HELP ASAP

Determine whether the set of whole numbers is closed under addition. explain why the set is or is not closed. give an example.

3.17 scores on stats final. below are final exam scores of 20 introductory statistics students. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 57, 66, 69, 71, 72, 73, 74, 77, 78, 78, 79, 79, 81, 81, 82, 83, 83, 88, 89, 94 (a) the mean score is 77.7 points. with a standard deviation of 8.44 points. use this information to determine if the scores approximately follow the 68-95-99.7% rule. (b) do these data appear to follow a normal distribution? explain your reasoning using the graphs provided below.

What is the value for this expression? 2e-5