Question

ANSWER PLEASE FINAL DUE IN 3 HOURS

Suppose a normal distribution has a mean of 120 and a standard deviation of 10. What is P(x ≥ 130)?


A.
0.475

B.
0.84

C.
0.16

D.
0.975

Answer 1

0.16

Explanation:

Answer 2

B

Explanation:

First thing to do here is to calculate the z-score

Mathematically;

z-score = (x-mean)/SD

here, x = 130, mean = 120 and SD = 10

Substituting these values

z-score = (130-120)/10 = 10/10 = 1

So the probability we want to calculate is;

P(z ≥ 1) = 1 - P(z <1)

From standard score table, P(z <1) = 0.15866

P(z ≥ 1) = 1-0.15866 = 0.84134