Posted by Kcr7 on .
A set of 50 data values has a mean of 15 and a variance of 36.
Find the standard score of a data value = 30

statistics 
MathGuru,
Use zscores.
Formula:
z = (x  mean)/sd
Your data:
x = 30
mean = 15
sd = square root of the variance
I'll let you take it from here.