If the z-value for a given value of x

Question

If the z-value for a given value of x of the random variable x is z = 2.12 and x is normally distributed with a mean of 70 and a variance of 25, to what x-value does this z-value correspond?

Answer 1

z score = (given x value - mean)/(standard deviation)

 

Since the variance = 25, the standard deviation = √variance = 5

 

So, 2.12 = (x - 70)/5

 

       10.60 = x - 70

 

        x = 80.60