The answer is:
Both have the same number of data points
Both means are between 3 and 4
Westwood has less variability than Middleton
Account A.....with 250 checks
0.20(250) = 50
Account B...with 250 checks
0.10(250) + 1.50 = 25 + 1.50 = 26.50
so by using Account B, u r saving (50 - 26.50) = 23.50
Answer:
a=2 and b=2...............