Types of Graphs Creating a Graph With Microsoft Excel
Line Graphs • Line graphs compare two variables (One is usually time) • Given one variable the other can easily be determined • Show trends in data and show how one variable is affected by the other as it increases or decreases • They enable the viewer to make predictions about the results of data not yet recorded
Bar Graphs • Make comparisons between different groups (variables) very easy to see.
Scatter plot graphs • Use horizontal and vertical axes to plot X-Y data points • Scatter plots show how much one variable is affected by another. The relationship between two variables is called their correlation . • Scatter plots usually consist of a large body of data. The closer the data points come when plotted to making a straight line, the higher the correlation between the two variables, or the stronger the relationship.
Scatter plot graphs • A perfect positive correlation is given the value of 1 • A perfect negative correlation is given the value of –1
Scatter plot Graphs If there is absolutely no correlation present then R2 = 0 The closer R2 is to 1 or -1, the stronger the correlation, or the stronger the relationship between the variables The closer R2 is to 0, the weaker the correlation
Creating Graphs With Microsoft Excel
Step 1 Launch Excel Open a new Excel workbook Click on the NewWorkbook button.
Step 4 Select the Chart Wizard Click Here
Step 5From the Chart Wizard box that opens select Chart type Click & Hold to view sample graph
Step 8Click on As new sheet Click here to have your graph use the whole page
Now make a Bar graph using the same data • Click on sheet 1 • Repeat steps 2-8 to complete a bar graph • Print your graph to science cart laser • Write your name on the graph and hand in to Mr. Girard
Making a Scatter plot line graph • Plot the following data • Create a scatter-plot graph • Click on chart • Click on add trendline • Click on linear • Click options • Check Display equation on chart • Check R-squared value on chart • Print graph and hand in to Mr. Girard
Regression Line The closer the R2 Value is to 1.0 the better the fit to the data