Question

If the mean is subtracted from every number in a data set, and the differences are used to form a new data set, that data set must have a mean:

A. equal to the mean of the original data set
B. equal to zero
C. smaller than the mean of the original data set
D. larger than the mean of the original data set
E. cannot be determined by the information given

Answer 1

@ganeshie8

Answer 2

well just try it....

pick 3 numbers say 5, 8, 17

whats the mean..?

what is the mean of the differences..?

Answer 3

try another set and see if your conclusions hold true

Answer 4

I tried that and i got a smaller number (c) but i wasn't sure if thats always true

Answer 5

I tried that and i got a smaller number (c) but i wasn't sure if thats always true

Answer 6

(5 + 8 + 17)/3 = 10

5 - 10 = -5

8 - 10 = -2

17 - 10 = 7

add them up and they add to zero...

so go and test it with another data set

Answer 7

(1+4+9+10)/4= 6
1-6= -5
4-6= -2
9-6= 3
10-6= 4
ok i got zero for these

Answer 8

so would that make it B? @campbell_st

Answer 9

so it seems to be a thing... so the sum of the differences is 0

now divide by the number of terms... to get the mean

in my example 0/3 = 0

your example 0/4 = 0

Answer 10

so am i right then?