Line Plots and Line Plots and HistogramsHistograms

Similar but DifferentSimilar but Different

Line PlotsLine Plots

Easy and visual way to organize Easy and visual way to organize data.data.

consists of a horizontal number line,consists of a horizontal number line, each value marked by an x over the each value marked by an x over the

corresponding value on the number corresponding value on the number line. line.

The number of x's above each The number of x's above each number indicates how many times number indicates how many times each number occurred.each number occurred.

Watch! Don’t write yet!Watch! Don’t write yet!

Data SetData Set58, 30, 37, 36, 34, 49, 35, 40, 47, 47, 39, 54, 47, 48, 54, 58, 30, 37, 36, 34, 49, 35, 40, 47, 47, 39, 54, 47, 48, 54, 50, 35, 40, 38, 47, 48, 34, 40, 46, 49, 47, 35, 48, 47, 4650, 35, 40, 38, 47, 48, 34, 40, 46, 49, 47, 35, 48, 47, 46

First put them in numerical order.First put them in numerical order.

30, 34, 34, 35, 35, 35, 36, 37, 38, 39, 40, 40, 40, 46, 46, 30, 34, 34, 35, 35, 35, 36, 37, 38, 39, 40, 40, 40, 46, 46, 47, 47, 47, 47, 47, 47, 48, 48, 48, 49, 49, 50, 54, 54, 5847, 47, 47, 47, 47, 47, 48, 48, 48, 49, 49, 50, 54, 54, 58

Now create your graph.Now create your graph.

30 35 40 45 50 55 60

•Find the range of the Data and decide what increments would best show the data.

•It would be silly to make a graph in increments of one.

•It would be unnecessary to make the graph go to 100.

Add the DataAdd the Data

Place an X over the number as it Place an X over the number as it appears in your data setappears in your data set

30, 34, 34, 35, 35, 35, 36, 37, 38, 39, 40, 40, 40, 46, 46, 47, 47, 47, 47, 47, 47, 48, 48, 48, 49, 49, 50, 54, 54, 58

So What?So What?

The Line Plot allows us to see The Line Plot allows us to see some trends more clearly.some trends more clearly.

Outliers - data points whose values are significantly larger or smaller than other values.

Clusters - isolated groups of points Gaps - large spaces between points

Which are Which are OutliersOutliers??

Which are Which are ClustersClusters??

Where are Where are GapsGaps??

30 and 58

34-35 and 46-50

Between 40 and 46

Between 50 and 54

Try it !Try it !

Data SetData Set

30,36, 74, 36, 77, 80 36, 45, 36, 30,36, 74, 36, 77, 80 36, 45, 36, 36, 37, 38, 38, 50, 38, 39, 42, 42, 36, 37, 38, 38, 50, 38, 39, 42, 42, 45, 45, 45, 45, 45, 48, 36, 50, 50, 45, 45, 45, 45, 45, 48, 36, 50, 50,

51,52, 38, 52, 74, 77, 51,52, 38, 52, 74, 77,

Put in Numerical OrderPut in Numerical Order

30,36, 36, 36, 36, 36, 36, 37, 30,36, 36, 36, 36, 36, 36, 37, 38,38, 38, 38, 39, 42, 42, 45, 45, 38,38, 38, 38, 39, 42, 42, 45, 45,

45, 45, 45, 45, 48, 50, 50, 50, 45, 45, 45, 45, 48, 50, 50, 50, 51,52, 52, 74, 74, 77, 77,8051,52, 52, 74, 74, 77, 77,80

Make a Number Line and PlotMake a Number Line and Plot

30 35 40 45 50 55 60 65 70 75 80

30,36, 36, 36, 36, 36, 36, 37, 38,38, 38, 38, 39, 42, 30,36, 36, 36, 36, 36, 36, 37, 38,38, 38, 38, 39, 42, 42, 45, 45, 45, 45, 45, 45, 48, 50, 50, 50, 51,52, 52, 42, 45, 45, 45, 45, 45, 45, 48, 50, 50, 50, 51,52, 52, 74, 74, 77, 77,8074, 74, 77, 77,80

Fill in the x’s in your notes. It’s too hard to do it in a PowerPoint!

HistogramHistogram

FREQUENCY is the keyFREQUENCY is the key Measure Frequency of dataMeasure Frequency of data Like a bar graph but measures the Like a bar graph but measures the

number of times the data occurs. number of times the data occurs. Think of a Connect Four game.Think of a Connect Four game. Every time a number is in the data, Every time a number is in the data,

you drop a checker in the game. you drop a checker in the game.

Bar Graph or Histogram?Bar Graph or Histogram?

This is a histogram of how many employees make a certain amount of money. Every time there is another employee in a salary category, the histogram gets taller.

Bar GraphsBar Graphs

The y axis is showing Dollars not Frequency. This is not a histogram.

Bar Graph or HistogramBar Graph or Histogram

We want to compare total revenues of five different companies.

Bar graph. Key question: What is the revenue for each company?

Bar Graph or HistogramBar Graph or Histogram We have measured revenues of several companies. We want to

compare numbers of companies that make from 0 to 10,000; from 10,000 to 20,000; from 20,000 to 30,000 and so on.

Histogram. Key question: How many companies are there in each class of revenues?

Try OneTry One

Data for the age of kids going on the Data for the age of kids going on the merry-go-round.merry-go-round.

2,3,10,5,3,7,9,4,4,10,6,3,4,8,10,2,3,10,5,3,7,9,4,4,10,6,3,4,8,10,