D Frequency Charts & Interval Ranges

Tallies are a way to mark the occurance of a vote for a

catagory. The number representing the tallies is a

frequency. A cumulative frequency is a running total

of votes or occurances. Study the frequency chart on

the next slide and prepare to complete your own.

Then complete the chart on the slide after next. Now

click okay to continue.

Frequency charts

Tally Frequency Cumulative Frequency

7 + 3 = 10

10 + 6 = 16

26 + 8 = 34

16 + 10 = 26

34 + 2 = 36

Tally Frequency Cumulative Frequency

Again...

Tallies are a way to mark the occurance of a vote for a

catagory. The number representing the tallies is a

frequency. A cumulative is a running total

of votes or occurances. This tells how many total votes

or occurances there were. After reading this slide click

okay.

Frequency charts

Histograms are similar to bar graphs except they

group data into ranges. This is handy when data can't

easily be divided into categories. An example would be

runners finishing a race. Times may be too spread out

for categories. Therefore, intervals are used instead.

Your benchmark exams are divided into intervals of

20 as follows.

1-20

21-40

41-60

61-80

81-100

The interval range for this data is .

Each interval must have the same range. When

we subtract the low from the high, we must have the

same range. Complete the chart below.

10 - 14

15 - 19

20 - 24

5 - 9

0 - 4

The interval range is the high

of any row minus the low

of the same row.

The interval range for this data is .

9 - 12

13 - 16

17 - 20

5 - 8

1 - 4

The interval range is the high

of any row minus the low

of the same row.

The interval range for this data is .

21 - 30

11 - 20

31 - 40

41 - 50

1 - 10

The interval range is the high

of any row minus the low

of the same row.

The interval range for this data is .

101 - 125

51 - 75

26 - 50

76 - 100

1 - 25

The interval range is the high

of any row minus the low

of the same row.