Scores for an exam are normally distributed with a mean of 235 and a standard deviation of 52.Then the score which corresponds to the bottom 24% is 199 or lower.

Question

Quizplus · Accepted Answer

This is true because when 24% of the scores fall below the score we are interested in, we can find the corresponding z-score using a standard normal distribution table. The z-score corresponding to the bottom 24% is approximately -0.73. We can then use the formula z = (x - μ) / σ to solve for x, the corresponding score. Plugging in the values, we get -0.73 = (x - 235) / 52, which gives x = 199.6. Since we are looking for the bottom 24%, any score at or below 199 would be included, so the statement is true.

Scores for an Exam Are Normally Distributed with a Mean