An interquartile range is finding the median of the first half of the data set, and the second half, then subtracting the first median from the second one.
B is the answer because there are 52 weeks in a year so $52,000/52 gives 1,000 and 1,000/40 gives 25. It's not A because it can't be less that $25 but more than it.
Rewrite the equation in standard form: y = (5/9)x+(8/9). [y=mx+b]
A line perpendicular to this would have a slope that is the negative inverse of the original slope (5/9), which would make it -(9/5). The y-intercept would also change, but we don't know the value, yet. For now, we'll use "b" for the y-intercept. This results in a perpendicular line:
y = -(9/5)x + b
We can calculate b, the y-intercept, by using the point (-5,8) and solving for b.
8 = -(9/5)*(-5) + b
8 = (9) + b
b = -1
The line perpendicular to 5x−9y=−8 that passes through the point (−5,8) is