Answer:
87
Step-by-step explanation:
95 - 7 = 87
The percentage of U.S. states that start with a w is 8%
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
What are you supposed to solve
The explicit formula for a arithmetic sequence is a_n = a_1 + (n - 1)d.
We want to find a_21.
a_21 = 17 + (21 - 1)(10)
a_21 = 17 + (20)(10)
a_21 = 17 + 200
a_21 = 217
The 21st term is 217.