Wait times at an orthodontist's office are typically 17 minutes, with a standard deviation of 2 minutes. What percentage of people should be seen by the doctor between 11 and 23 minutes for this to be considered a normal distribution?

17%
68%
95%
99.7%

99.7%

Step-by-step explanation:

The Empirical Rule states that, for a normally distributed random variable:

68% of the measures are within 1 standard deviation of the mean.

95% of the measures are within 2 standard deviation of the mean.

99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we have that:

Mean = 17

Standard deviation = 2.

What percentage of people should be seen by the doctor between 11 and 23 minutes for this to be considered a normal distribution?

11 = 17 - 3*2

So 11 is 3 standard deviations below the mean

23 = 17 + 2*3

So 23 is 3 standard deviations above the mean.

By the Empirical Rule, 99.7% of people should be seen by the doctor between 11 and 23 minutes for this to be considered a normal distribution.

So the correct answer is:

99.7%