Frequency Distributions

Question 1

Frequency distribution

Answer 1

Frequency tables/charts
Organizes infomation by score (high to low)
Makes it easier to calculate dataset’s range (highest - lowest = range)

Question 2

Grouped frequency distribution

Answer 2

Scores are grouped into larger intervals
Interval width: how many values are represented by interval

Question 3

How many intervals are recommended in grouped frequency distribution?

Answer 3

10-20 intervals or square root of N
choose a meaningful interval width

Question 4

Relative frequency distribution

Answer 4

indicates the proportion of the total number of scores that occurs in each interval

Relative f = f/N

Question 5

Cumulative frequency distribution

Answer 5

indicates the number of scores that fall below the upper limit of each interval

add up all the numbers on and below the row

Question 6

Cumulative percentage distribution

Answer 6

indicates the percentage of scores that fall below the upper limit of each interval

cum% = (cum f / N) x 100

Class interval f Relative f Cumulative f Cum %
95-99 4 .06 70 100
90-94 6 .09 66 94.29
–> 94.29% of the scores are less than or equal to 94