Answer:
About 68% of college students typically sleep between 5.3 and 8.7 hours per night.
About 95% of college students typically sleep between 3.6 and 10.4 hours per night.
About 99.7% of college students typically sleep between 1.9 and 12.1 hours per night.
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 = 7
Standard deviation = 1.7
7 + 1*1.7 = 8.7
7 - 1*1.7 = 5.3
About 68% of college students typically sleep between 5.3 and 8.7 hours per night.
7 + 2*1.7 = 10.4
7 - 2*1.7 = 3.6
About 95% of college students typically sleep between 3.6 and 10.4 hours per night.
7 + 3*1.7 = 12.1
7 - 3*1.7 = 1.9
About 99.7% of college students typically sleep between 1.9 and 12.1 hours per night.