Question

Scores on a standardized exam are normally distributed with a mean of 63 and a standard deviation of 7. Consider a group of 6000 students. Approximately how many students will score less than 71 on the exam?

Answer 1

5238 students

Explanation:

Finding the z-score:

z = (x - μ) / σ

Let x be the value to be evaluated, which is 71. μ is the mean, σ is the standard deviation, which is 7. replacing we are left with:

z = (71 - 63) / 7

z = 1.14

Using a z-score table or calculator:

P (z <1.14) = 0.8729

87.29% of 6000 is:

0.8729 * (6000) = 5237.4

Rounding off we have approximately 5238 students