Statistic Question

Question

The time to complete an exam is approximately Normal with a mean of 42 minutes and a standard deviation of 3 minutes.

The bell curve below represents the distribution for testing times. The scale on the horizontal axis is equal to the standard deviation. Fill in the indicated boxes.

Answer 1

If 42 minutes is the mean with standard deviation equal to 3 minutes Then:

only .27 percent of the population falls outside the range of 33 minutes and 51 minutes ( plus minus 3 standard deviations)

Answer 2

I'm not sure what you mean by "indicated boxes". If you are looking for what the values of µ and σ, then you need to know that µ is the symbol for mean, and σ is the symbol for standard deviation. The mean and standard deviation are given in the problem as µ = 42 and σ = 3.