a. What percent of people earn less than $40000?
Solution: Let S be the random variable of a salary of employee (in $), S ~ N(50000,20000). Then the random
variable X =−50000
20000
~N(0,1).
( < 40000) = ( <
40000 − 50000
20000 ) = ( < −0.5) = (−0.5) = 0.3085375.
Here Φ(x) denotes the cumulative distribution function of a standard normal distribution.
Answer: 31%.
b. What percent of people earn between $45000 and $65000?
Solution:
(45000 < < 65000) = (
45000 − 50000
20000 < <
65000 − 50000
20000 ) = (−0.25 < < 0.75)
= (0.75) − (−0.25) = 0.7733726 − 0.4012937 = 0.3720789.
Answer: 37%.
c. What percent of people earn more than $70000?
Solution:
( > 70000) = ( >
70000 − 50000
20000 ) = ( > 1) = 0.8413447.
Answer: 84%.
<z = 180 - 43
<z = 137
answer
<z = 137 degrees
Answer:
![{27}^{ \frac{1}{3} } = \sqrt[3]{27} = \sqrt[3]{3 \times 3 \times 3} = \boxed{ 3}✓](https://tex.z-dn.net/?f=%20%7B27%7D%5E%7B%20%5Cfrac%7B1%7D%7B3%7D%20%7D%20%20%3D%20%20%5Csqrt%5B3%5D%7B27%7D%20%20%3D%20%20%5Csqrt%5B3%5D%7B3%20%5Ctimes%203%20%5Ctimes%203%7D%20%20%3D%20%5Cboxed%7B%203%7D%E2%9C%93)
<h3>3. <em><u>3</u></em> is the right answer.</h3>
A + b + c = 72
a = b - 1
c = b + 1
(b - 1) + b + (b + 1) = 72
Simplify
3b = 72
b = 24
a = 24 - 1
a = 23
