Answer:
.For about 68% of students, nightly amount of sleep is between __4____and ___6__ hours.For about 95% of students, nightly amount of sleep is between __3____and __7___ hours.For about 99.7% of students, nightly amount of sleep is between ___2___and __8___ hours.
Step-by-step explanation:
The empirical rule tells us that for normal distributions,
68% of data lie within one standard deviation of the mean.
Thus, 68% of data lie within
⇒ 5 ± 1 = (4, 6) hours
Similarly, 95% of data lie within two standard deviation of the mean.
Thus, 95% of data lie within
⇒ 5 ± 2 = (3, 7) hours
99.7% of data lie within one standard deviation of the mean.
Thus, 99.7% of data lie within
⇒ 5 ± 3 = (2, 8) hours