Let x represent the scores. With mean and standard deviation given,
The Empirical rule states that
1) About 68% of the x values lie between 1 standard deviation below and above the mean
2) About 95% of the x values lie between 2 standard deviation below and above the mean
3) About 99.7% of the x values lie between 3 standard deviation below and above the mean
If we consider this rule, then the percentage of scores that fall within 3 standard deviation (-3 to +3) is 99% because this is closer to 99.7%
P-23=-3
+23 +23
P=20
so the answer is A
She can have 7 days off at most because 3 X 1250 = 3750 - 700 = 3050
Multiply 9 by 2a and 2, and you get 18a + 18. Another equivalent expression would be 18(a+1), which you can get by factoring the above answer.
Answer : C
6 2 over 3 units
