Question

The time to complete an exam is approximately Normal with a mean of 49 minutes and a standard deviation of 9 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

Given:

The time to complete an exam is approximately Normal with a mean of 49 minutes and a standard deviation of 9 minutes.

So,

Given the following figure of the bell curve represents the distribution for testing times.

We will fill in the indicated boxes as follows by calculating the value of each box:

`\begin{gathered} \mu-3\sigma=49-3\cdot9=22 \\ \mu-2\sigma=49-2\cdot9=31 \\ \mu-\sigma=49-9=40 \\ \mu=49 \\ \mu+\sigma=49+9=58 \\ \mu+2\sigma=49+2\cdot9=67 \\ \mu+3\sigma=49+3\cdot9=76 \end{gathered}`