Question

A high school teacher collected the final test scores of students in her Honors United States History course. She found that the scores were normally distributed with a mean of 70 and a standard deviation of 10. What percentage of her students passed the exam with a score of 60 or above

Answer 1

0.84134

Explanation:

Given that:

Mean, m = 70

Standard deviation, s = 10

P(x ≥ 60)

Obtain the standardized score (Zscore) :

Z = (x - m) / s

Z = (60 - 70) / 10

Z = - 10 / 10

Zscore = - 1

P(Z ≥ 1) = 0.84134 (Z probability calculator)