# Frequency Tables Histograms

## Presentation on theme: "Frequency Tables Histograms"— Presentation transcript:

Frequency Tables Histograms
Reporting Frequency Frequency Tables Histograms

What is a Frequency Table?
A Frequency table is a table that lists each item in a data set with the number of times it occurs.

Construct a Frequency Table (tally sheet)
7, 10, 10, 9, 8, 9, 7, 4, 3, 7, 10, 4, 8, 9, 6, 7, 10 Enter the data value into the 1st column Data Value Tally Frequency 1 2 3 4 5 6 7 8 9 10

Construct a Frequency Table (tally sheet)
7, 10, 10, 9, 8, 9, 7, 4, 3, 7, 10, 4, 8, 9, 6, 7, 10 Enter a tally for each entry. Data Value Tally Frequency 1 2 3 4 5 6 7 8 9 10

Construct a Frequency Table (tally sheet)
Count the tallies and put the total for each value in the frequency column Data Value Tally Frequency 1 2 3 4 5 6 7 8 9 10 1 2 1 4 2 3 4

Construct a Frequency Table (tally sheet)
We can find the percent in each row by dividing by the total. Count the tallies and put the total for each value in the frequency column Data Value Tally Frequency Percent 1 2 3 4 5 6 7 8 9 10 1 6% 1/17=0.058 2 12% 2/17=0.117 1 6% 1/17=0.058 4 24% 4/17=0.235 2 12% 2/17=0.117 3 18% 3/17=0.176 4 24% 4/17=0.235 17

Making a Line plot x x x x x x x x x x x x x x x x x 3 4 5 6 7 8 9 10
What is the range? 7

What is a Histogram? A histogram is a bar graph with no spaces between the bars. The height of each bar shows the frequency of data within that interval. The intervals of a histogram are of equal size and do not overlap.

Histogram Class Test Scores Frequency Test Scores

Histograms 95 flashlights are tested until they fail. The table gives the times taken ( hours ) until failure. Time to failure (hours) 0-19 20-29 30-39 40-44 45-49 50-59 60-89 Number of components 5 8 16 22 18 10 Find 2 or more things wrong with the histogram which represents the data in the table.

Histograms Answer: Time to failure (hours) 0-19 20-29 30-39 40-44 45-49 50-59 60-89 Number of components 5 8 16 22 18 10 Time taken for 95 components to fail There is no title. There are no units on the x-axis. Time to failure (Hours)

Line Plot Favorite Colors X X X X X X X X X X X X X
Red Blue Green Yellow Purple

Histogram Histograms are used to show the frequency of data.
Very similar to bar graphs, but use intervals on the X axis. Bars do touch. Histograms have a title. Histograms have two axes which are labeled.

Frequency Tables Histograms
Reporting Frequency Frequency Tables Histograms