Question

a survey of high school students found that the mean number of text messages sent per day was 62 with a standard deviation of 12. If a normal distribution is assumed, which interval represents the number of texts sent by 68% of the students? A. 44-80 B. 56-68 C. 50-74 D. 38-86

Answer 1

In a normal distribution, approximately 68% of the data falls within one standard deviation of the mean. Given that the mean number of text messages sent per day is 62 and the standard deviation is 12, you can calculate the interval for 68% of the students as follows:

- The lower bound is: Mean - Standard Deviation = 62 - 12 = 50
- The upper bound is: Mean + Standard Deviation = 62 + 12 = 74

Thus, the interval that represents the number of texts sent by 68% of the students is from 50 to 74.

The correct answer is: **C. 50-74**.