Question

A simple random sample of 21 high school students was surveyed, and the number of participant with GPAs in a given range were recorded in the following table. Complete the table. Express all answers as decimals rounded to 3 decimal places (namely, rel. freq. and cum. rel. freq.).

GPA	Class Midpoint	Frequency	Rel. Freq.	Cumulative Freq.	Cumulative Rel. Freq.
0.0-0.9		3
1.0-1.9		5
2.0-2.9		7
3.0-3.9		6

a) Draw a frequency polygon for the GPAs of the students in the sample. Label the axes appropriately, including the scale used.

Answer 1

GPA	Class Midpoint	Frequency	Rel. Freq.	Cumulative Freq.	Cumulative Rel. Freq.
0.0-0.9	0.45	3	0.143	3	0.143
1.0-1.9	1.45	5	0.238	8	0.381
2.0-2.9	2.45	7	0.333	15	0.714
3.0-3.9	3.45	6	0.286	21	1

( a )

To draw Frequency Polygon, we first prepare the following table

Class	Mid	Frequency f
-0.9 - 0	-0.45	0
0 - 0.9	0.45	3
1 - 1.9	1.45	5
2 - 2.9	2.45	7
3 - 3.9	3.45	6
3.9 - 4.8	4.35	0