(a)What percent of the scores are less than 19? (b) out of 1500 randomly selected scores,about how many would be expected to be greater than 21

(a) 45.4%

(b) 591

Step-by-step explanation:

(a) μ = 19.6, σ = 5.2

First, find the z-score.

z = (x − μ) / σ

z = (19 − 19.6) / 5.2

z = -0.115

Use a chart or calculator to find the probability.

P(Z < -0.115) = 0.454

45.4% of the scores are less than 19.

(b) First, find the z-score.

z = (x − μ) / σ

z = (21 − 19.6) / 5.2

z = 0.269

Use a chart or calculator to find the probability.

P(Z > 0.269) = 1 − P(Z < 0.269)

P(Z > 0.269) = 1 − 0.606

P(Z > 0.269) = 0.394

39.4% of the scores are greater than 21.  There are 1500 scores, so 39.4% of that is 591.

The answer is D: 7 1/2.

Step-by-step explanation: