Chapter 6, Problem 23E

To determine

To explain the scenario.

Answer to Problem 23E

6 years standard deviation would be allowed.

Explanation of Solution

We need think about all the standard deviations. We will check it one by one.

If the SD was 16 years, then it might be normal for the number of years teaching to vary between 16 years below and 16 years above the mean. Let us assume the average age of a professor is 40. this would mean that it is fairly for a professor to begin teaching at age 40-32 = 8. Therefore, it does not look realistic.

Therefore, 6 months will be too small. This would mean that a variability on the order of 3 years is almost unheard of. In general, there are constantly new teachers coming in, who would start at 0. If the average number of years teaching is above 4, then the 6 months SD would not be realistic.

Hence, we can say the 6 yearsstandard deviation is the most likely. It allows for moderate variability.