Question

Suppose a normal distribution has a mean of 79 and a standard deviation of 7. What is P(x > or = to 86)?

Answer 1

Answer:

P(X >= 86) =  P (Z  >= 1) = 0.1587 from the Z-scores table

Step-by-step explanation:

Hopefully this time I will not make an algebraic mistake.

Ok

so  mean u = 79,  and standard dev = s = 7

We want P(X >= 86)

Standardize:

P ( (X - u)/s  >=  (86 - 79)/7 ) =  P (Z  >= 1) = 0.1587 from the Z-scores table