Two data sets are shown set a: 45,65,66,67,68,68,69,70,70 set b: 40,41,43,45,46,47,48,49,49 the mean of set a is 65.6 the mean of set b is 45 (please help!!)

Set A : 45, 65, 66, 67 ,68, 68, 69, 70, 70

Median = 68

Set B : 40, 41, 43, 45, 46, 47, 48, 49, 49

Medain = 46

When 45 is removed from both

Set A : 65, 66, 67 ,68, 68, 69, 70, 70

Median = 68

Set B : 40, 41, 43, 46, 47, 48, 49, 49

Medain = 46.5

Set A : 45, 65, 66, 67 ,68, 68, 69, 70, 70

Mean = 65.33

Set B : 40, 41, 43, 45, 46, 47, 48, 49, 49

Mean = 45.33

when 45 is removed from both

Set A :  65, 66, 67 ,68, 68, 69, 70, 70

Mean  = 67.875

Set B : 40, 41, 43, 46, 47, 48, 49, 49

Mean = 45.38

The difference between median of A and B decreases because the median of set B increases.

The difference between mean of A and B increases because the mean of set A increases.

you can first factor out the n to get n(1+5). we know that 1+5 is 6, so we just have 6n.