A set of N = 10 scores has a mean of µ = 50.If 20 points are added to one of the scores,what is the new value for the population mean?
A)50
B)51
C)52
D)70

Question

A set of N = 10 scores has a mean of µ = 50.If 20 points are added to one of the scores,what is the new value for the population mean?​
A)​50
B)​51
C)​52
D)​70

Quizplus · Accepted Answer

Adding 20 points to one of the scores increases the total sum of the scores by 20. To find the new population mean, we divide the total sum by the number of scores, which is still 10.

New total sum = Old total sum + 20 
New total sum = 10(50) + 20 
New total sum = 520

New population mean = New total sum / N 
New population mean = 520 / 10 
New population mean = 52

Therefore, the new value for the population mean is 52, which corresponds to choice C.

A Set of N = 10 Scores Has a Mean