Answer:
The coordinates of EF are E(5,-4) and F(1,-4).
The line segment EF is in QIV
Step-by-step explanation:
The line segment AB has vertices at: A(-4,5) and B(-4,1).
We apply the rule
to reflect AB in the y-axis to obtain CD.


We apply the rule
to rotate CD 90 degrees clockwise about the origin to obtain EF.


The coordinates of EF are E(5,-4) and F(1,-4).
See attachment
Steps
Step 1: For each (x,y) point calculate x2 and xy.
Step 2: Sum all x, y, x2 and xy, which gives us Σx, Σy, Σx2 and Σxy (Σ means "sum up")
Step 3: Calculate Slope m:
m = N Σ(xy) − Σx Σy N Σ(x2) − (Σx)2
Step 4: Calculate Intercept b:
b = Σy − m Σx N.
Step 5: Assemble the equation of a line.
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 $70000?
Solution:
( > 70000) = ( >
70000 − 50000
20000 ) = ( > 1) = 0.8413447.
Answer: 84%.
29.99 dollars because if you use a calculator subtracting 1.99.99 by 15% you get 29.998 but you can also round up to 30$