The monthly sales (in thousands of $) at a certain restaurant for the past two years are given in the chart below:
Last year: 9, 9.5, 10, 10, 11, 11, 11, 11, 11, 12.5, 13, 13.
This year: 9, X, 10, 10, 11, 11, 11, 11, 11, Y, 13, 13.
If the standard deviation of the monthly sales is greater this year than last year, which of the following are possible values for X and Y?
A) 9 and 12.5
B) 10 and 11
C) 10 and 12.5
D) 11 and 11
E) 11 and 12.5
The OA is A.
Please, can any expert explain this PS question for me? I have many difficulties to understand why that is the correct answer. Thanks.
Last year: 9, 9.5, 10, 10, 11, 11, 11, 11, 11, 12.5, 13, 13.
This year: 9, X, 10, 10, 11, 11, 11, 11, 11, Y, 13, 13.
If the standard deviation of the monthly sales is greater this year than last year, which of the following are possible values for X and Y?
A) 9 and 12.5
B) 10 and 11
C) 10 and 12.5
D) 11 and 11
E) 11 and 12.5
The OA is A.
Please, can any expert explain this PS question for me? I have many difficulties to understand why that is the correct answer. Thanks.
