Fine the lower and upper quartiles and interquetile range. 5, 12, 17, 23, 28, 31, 37, 41, 42, 49, 54, 58, 65, 68, 73, 71.

Lower Quartile = 25.5

Upper Quartile = 61.5

IQR = 36

Step-by-step explanation:

Given data is:

5, 12, 17, 23, 28, 31, 37, 41, 42, 49, 54, 58, 65, 68, 73, 71

The lower quartile is the first quartile and upper quartile is the third quartile.

A median divides the data set in two equal halves.

Lower quartile also known as first quartile is the middle value in the first half.

The first half is:

5, 12, 17, 23, 28, 31, 37, 41

As the number of values is even, the quartile will be the average of two middle values

Upper quartile is the average of middle two values in the second half when the number of values is even.

42, 49, 54, 58, 65, 68, 73, 71

Interquartile range is the difference of third quartile and first quartile

Hence,

Lower Quartile = 25.5

Upper Quartile = 61.5

IQR = 36

Put the equation into slope intercept form so you can find the slope.
5x+3y=8
3y=-5x+8
y=-5/3x+8/3
The slope of this line is -5/3. 
The slope of the line perpendicular to it is the negative reciprocal, which is:
slope= 3/5
Hope this helps.