BellRingerHomework Check

• Place your homework on your desk- “Choosing an Appropriate Graph”

• Take out two sheets of notebook paper for notes.

• Take out one sheet of graph paper.• You need a pencil today!

Constructing and Analyzing Bar Graphs

& Units of Measurement

Guidelines for Making a Bar Graph

• Bar Graphs are perfect for showing information that shows quantities or numbers, or the frequency of things

• Bar Graphs may also be used to show changes over time or to compare items with one another.

Review

Guidelines for Making a Bar Graph

Step 1: Identify the variables.

Independent variable – factor the is changed on purpose by the experimenter

Dependent Variable- factor that changes because of the independent variable

and is measured

Guidelines for Making a Bar Graph

Step 2: Determine the variable range.

Subtract the lowest value from the highest value for the dependent variable.

Guidelines for Making a Bar Graph

Step 3: Determine the scale of the graph.Determine the numerical value for each grid unit

(square) on your graph paper that best fits the range (from step 2) of each variable.

Formula: (y-axis) Grid unit = Data range / #of lines on your graph paper

Determine the number and width of bars on graph (x- axis)

Evenly space all bars.

Guidelines for Making a Bar Graph

Step 5: Number and label the y-axis & label the x-axisNumber the y-axis according to the scale from step 4.

Label the y-axis including units of measurement when necessary.

Label the x-axis and each bar on the x-axis including units of measurement when necessary.

Guidelines for Making a Bar Graph

Step 6: Determine the data points and create the bar graph.

Remember to evenly space all bars.

Guidelines for Making a Bar Graph

Step 7: Provide a number and descriptive title for the bar graph.

Title fomat: Figure #: The effect of ___IV____ on___DV____.

Let’s Make a Bar GraphCopy the data table below onto aseparate sheet of paper.

Detergent Brand

Size of Bubbles (cm) Average Size of

Bubbles (cm)

Trial 1 Trial 2 Trial 3 Trial 4

A 44.0 38.9 30.8 29.4 35.8B 25.6 30.2 23.3 20.1 24.8C 10.0 15.4 21.6 12.9 15.0

• Examine each graph carefully.

• What was tested, changed, or compared

(INDEPENDENT VARIABLE) is plotted on

the X-axis.

• The data that was observed & measured (DEPENDENT VARIABLE) is plotted on the

Y-axis.

• The title and the label on the X-axis tells us that the type of fertilizer was tested in this experiment (Independent variable).

• The Y-axis tells us that plant height was measured in centimeters in this experiment (Dependent variable).

What is What is This This

Graph Graph About?About?

• Since there is a difference in the heights of the plants that received different fertilizers, we can say that there seems to be a relationship between plant height and type of fertilizer.

• The independent variable (type of fertilizer) affected the dependent variable (plant height).

• Super Gro seems to be the best fertilizer for plant growth.

AnalysisAnalysisAnd And

ConclusionConclusion

• The title and the label on the X-axis tells us that the types of degrees earned at colleges and universities between 1999 and 2000 were compared.

• The Y-axis tells us the number of people earning these degrees was measured.

• There is a significant difference between the number of people graduating with business degrees and the number of people graduating with other types of degrees.

• We can say that the type of degree or discipline division (independent variable) affects the number of people that get a certain degree (dependent variable).