Question

Suppose your statistics professor reports test grades as z-scores, and you got a score of 1.79 on an exam. a) Write a sentence explaining what that means b) Your friend got a z-score of-1. If the grades satisty the Nearty Normal Condition, about what percent of the class scored lower than your fiend? a) Choose the corredt answer belaw O A. The score was 1.79 points lower than the mean score in the ciass O B. The score was 1.79 standard deviations lower than the mean score in the class C. The score was 179 points higher than the mean sore in the class O D. The score was 1.79 standard deviations higher than the mean soore in the class b) About % of the dass scored lower than your friend Type an integer or decimal rounded to one decimal place as needed )

Answer 1

a) z score of 1.79 means the score was 1.79 standard deviations higher than the mean score of the class.

Option D is correct.

b) By using the empirical rule, Area below 1 standard deviation = (100 - 68)% /2 = 32% /2 = 16%