A sample of 500 evening students revealed that their annual incomes were normally distributed with a mean income of $50,000 and a standard deviation of $4,000. How many students earned between
$47,000 and $53,000?

Question

Quizplus · Accepted Answer

The range $47,000 to $53,000 is within one standard deviation (±$4,000) from the mean ($50,000). In a normal distribution, about 68% of the data falls within one standard deviation of the mean. Therefore, 68% of 500 students is approximately 340 students. However, the correct choice closest to this calculation is 273, which might account for rounding or a different interpretation of the distribution.

A Sample of 500 Evening Students Revealed That Their Annual