Question

the time to complete an exam is approximately normal with a mean of 39 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. μ = 39 σ = 3

Explanation:

Step1: Calculate \(\mu - 3\sigma\)

Given \(\mu = 39\) and \(\sigma=3\), then \(\mu - 3\sigma=39-3\times3 = 39 - 9=30\)

Step2: Calculate \(\mu - 2\sigma\)

\(\mu - 2\sigma=39-2\times3=39 - 6 = 33\)

Step3: Calculate \(\mu-\sigma\)

\(\mu-\sigma=39 - 3=36\)

Step4: Calculate \(\mu+\sigma\)

\(\mu+\sigma=39+3 = 42\)

Step5: Calculate \(\mu + 2\sigma\)

\(\mu + 2\sigma=39+2\times3=39 + 6=45\)

Step6: Calculate \(\mu+3\sigma\)

\(\mu + 3\sigma=39+3\times3=39 + 9 = 48\)

Answer:

30, 33, 36, 39, 42, 45, 48