A small computing center has found that the number of jobs submitted per day to its computers has a mean of 65 jobs and a standard deviation of 7. Where do we expect the number of jobs per day to fall most of the time (95.4%)?
A) between 58 and 72 jobs per day
B) between 51 and 79 jobs per day
C) between 44 and 86 jobs per day
D) between 51 and 86 jobs per day

Question

A small computing center has found that the number of jobs submitted per day to its computers has a  mean of 65 jobs and a standard deviation of 7. Where do we expect the number of jobs per day to fall most of the time (95.4%)?
A) between 58 and 72 jobs per day
B) between 51 and 79 jobs per day
C) between 44 and 86 jobs per day
D) between 51 and 86 jobs per day

Quizplus · Accepted Answer

The 95.4% confidence interval for a normal distribution corresponds to approximately ±2 standard deviations from the mean. Calculating 2 standard deviations from the mean (65 ± 2*7) gives us a range of 51 to 79 jobs per day.

A Small Computing Center Has Found That the Number of Jobs