Question

You survey 1000 new home buyers and find that the mean price was $185,000 and the standard deviation was $20,000. How many paid more than $210,000?

Answer 1

210000 - 185000 = 25000

25000 / 20000 = 1.25 s.d. above the mean
... this is the z-score

use a table to find the fraction above this z-score