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
