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%.
You can use 2 step equations to solve real-world problems by assessing the situation, trial and error, As in for example;
if you cannot open a twist off bottle cap by turning it to the right. You have two options twisted to the left to loosen or turn it to the right and not open it”
“ Lefty Lucy righty tightly”
Or if you are married and your husband cheats on you you can do one or two of the following stay or a go
For example stay and be an idiot or go and love yourself and take everything he has
Its A Random Trail With A Lot Of possible Come Outs
usually Denoted Using Set notations
You Can Use A Dice As And Example Or A Coin
Answer:
the constant of proportionality is 6.32
