Question

2. A standardized exam was provided to all 3rd graders in Arizona schools. The average score was 75 with a standard deviation of 10. Assuming that the scores were normally distributed, answer the following questions. (a) What z-score corresponds with a score of 75? (b) What z-score corresponds with a score of 80? (c) What z-score corresponds with a score of 85? (d) What z-score corresponds with a score of 100? (e) What percent of students scored between a 75 and 85? (f) What percent of students scored between a 70 and 85? (g) What percent of students received a score of 95 or higher?

Answer 1

Here is the process.

Z = (score-mean)/SD

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions/percentages related to the Z scores.

Answer 2

thanks for the answer