According to a survey of the top 10 employers in a major city, a worker spends an average of 413 minutes a day on the job. Suppose the standard deviation is 26.8 minutes and the time spent is approximately a normal distribution.
-Within which interval will the times of approximately 99.73% of all workers fall?
A)[305.8,520.2]
B)[386.2,439.8]
C)[372.8,453.2]
D)[359.4,466.6]
E)[332.6,493.4]

Question

Quizplus · Accepted Answer

The interval for approximately 99.73% of all workers falls within three standard deviations from the mean in a normal distribution. The mean is 413 minutes, and the standard deviation is 26.8 minutes. Three standard deviations from the mean is calculated as 3 * 26.8 = 80.4 minutes. Therefore, the interval is 413 - 80.4 to 413 + 80.4, which is 332.6 to 493.4.

According to a Survey of the Top 10 Employers in a Major