Chapter 02
HISTOGRAMS
Frequency Distributions and Their Graphs Here we will learn how to construct frequency distributions for quantitative data. Then we will learn how to construct histogram graphs from them. For these quantitative analyses, we will work with Exercise #27 from Section 2.2 of the text, entitled Hail to the Chief. 27. Hail to the chief: There have been 56 presidential inaugurations in U.S. history. At each one the president has made an inaugural address. Following are the number of words spoken in each of these addresses: 1425 135 2308 1729 2158 1175 1209 3217 4467 2906 1125 1172 3838 8445 4776 996 3319 2821 3634 698 1128 1337 2480 2978 1681 4388 2015 3967 2217 985 5433 1802 1526 3318 4059 3801 1883 1807 1340 559 2242 2446 2449 1355 1437 2130 1668 1087 2463 2546 2283 1507 2170 1571 2073 2406 Source: www.infoplease.comTo construct a histogram from a given data set, we have a six step procedure.Step 1. Enter the inaugural words spoken data in Column A and the Wait Bins in Column B. Wait Bins will be the class intervals. The first portion should look like the following (the spoken words data continues in Column A until cell A58, but the wait bins data is complete as seen): Step 2. Press Data, then Data Analysis. Select Histogram and click OK. If you do not see the Data Analysis menu to the very far right, go immediately to the Things to Watch Out For . . . section at the end of this chapter.Step 3. Enter the range of cells that contain the data in the Input Range field. You do so by left clicking the first cell of data in Column A and dragging the mouse down until “the moving screen” covers all 56 data values. Then, do the same for the Wait Bins data. Place those cells in the Bin Range box. Lastly, left click on any unused cell for the Output Range box. This is where Excel will place the frequency distribution. Notice below, we may choose to place the results in cell C3. Now, after clicking OK, we see the following frequency distribution:Step 4. Left click on each Bin cell and type in the following class intervals that you see below (in other words, replace 1000 with the interval 1-1000, replace 2000 with 1001-2000,…):Step 5. To get the histogram from this frequency distribution, first highlight all of the cells that make up the frequency distribution. It should look like the following (Note that Excel does not highlight in blue the first cell): Next click on Insert, then click on , then click on the left most graph under 2-D Column: This gives us the following bar graph:Step 6. To change from this bar graph to the appropriate histogram, double click on one of the bars on the actual bar graph. Then drag the Gap Width down to 0%. You should now see this: Finally, after hitting Close in the very bottom right, our histogram appears: | things to Watch Out For . . . | If in trying to construct a frequency distribution and histogram for quantitative data from Excel 2010, you do not see Data Analysis under the Data menu, you must activate it as an add-in. To do so, click on File, then click on Options, then click on Add-Ins. You should see under Inactive Application Add-ins, Analysis ToolPak. Click on this to bold it in blue, then type OK in the bottom right corner. You should now be able to proceed with creating frequency distributions and histogram graphs from them.Looking Forward . . . In the next chapter, we explore using Excel in Numerical Summaries of Data. | |