Final answer:
To sketch the normal curve showing wait times at one, two, and three standard deviations from the mean, determine the values at each deviation level using the given mean and standard deviation. Then, mark these wait times on the curve.
Step-by-step explanation:
To sketch the normal curve showing the wait times at one, two, and three standard deviations from the mean, we need to start by finding the values of the mean and standard deviation.
Given that the average wait time is 4.2 minutes and the standard deviation is 1.3 minutes, we can use these values to determine the wait times at one, two, and three standard deviations from the mean.
One standard deviation from the mean:
4.2 + 1.3 = 5.5 minutes (above the mean)
4.2 - 1.3 = 2.9 minutes (below the mean)
Two standard deviations from the mean:
4.2 + 2(1.3) = 6.8 minutes (above the mean)
4.2 - 2(1.3) = 1.6 minutes (below the mean)
Three standard deviations from the mean:
4.2 + 3(1.3) = 8.1 minutes (above the mean)
4.2 - 3(1.3) = 0.3 minutes (below the mean)
Using these values, you can now sketch the normal curve, where the mean (4.2 minutes) is the central point and the wait times at one, two, and three standard deviations from the mean can be marked on the curve.