Chapter 2: Data Representation

Question 1

Ungrouped Frequency Distribution

Answer 1

Freq. distribution with an interval width of 1.0, as opposed to intervals being grouped together with a range (9-11, 12-13)

Question 2

Width (of an interval)

Answer 2

the difference between the upper and lower real limits for an interval. w=URL-LRL

Question 3

Cumulative Frequency Distribution

Answer 3

the number of scores contained in that interval and all of the smaller intervals. The cf of a score of 17/20 would be the number scores between 0/20 up to and including 17/20.

Question 4

Relative Frequency Distribution

Answer 4

percentage of scores contained in that interval. For example, if 25 people took a 20pt test and 5 people had a score of 17, the rf of 17 would be rf=5/25=0.20

Question 5

Cumulative Relative Frequency (crf)

Answer 5

the percentage of scores in that interval and smaller. crf(12)=rf(9)+rf(10)+rf(11)+rf(12)