Name__________________________.

HW2, Math 320, Spring 98

Due Friday, January 23, 1998

1. (Like Exercise 2.22 page 53). Plot by hand on graph paper the e.d.f. for the data given in Exercise 2.12 page 47. Refer to your edf to answer the following questions:

1. Approximately what percentage of the weeks had fewer than 5 accidents?
2. Approximately what percentage of the weeks had fewer than 10 accidents?
3. What is the number of accidents per week that exceeds the number of accidents for approximately 80% of the weeks?

2. Do exercise 2.32 page 59 by hand on good graph paper (it will probably fit on the same sheet you used for the first problem). Answer the two questions posed in the problem. (Write in complete sentences. Strive to convey your interpretation of the data to the reader of your paper.)

3. Use Excel to do Exercise 2.54 page 71. Excel calls a scatterplot an xy-scatter chart. Here are instructions for doing this. Open a workbook a go to a fresh sheet. Enter Round 3 in cell A2 and Round 4 in cell B2. Enter the three columns under these labels just as they appear on page 71. Click on cell A2 and drag to highlight the whole block of data, including the labels. Click on the ChartWizard icon (the sixth icon from the right on the icon bar, looks like a vertical bar chart with a bubbling test tube over it). Follow the five steps ChartWizzard leads you through. At step five enter a Chart title and label the axes.

Calculator instructions: for the next two problems you need to use your calculator to find the sample mean and standard deviation of a set of data for a single variable. For the Sharp EL-546L, read pages 21 - 24 of its manual. As a tutorial, follow the worked out example on page 113 of the manual. Now is the time to learn how to use the statistical modes of your calculator, even though you could do the following problems without a statistical mode.

4. Do Exercise 3.10 page 82. Answer the question posed in the problem.

5. Do Exercise 3.16 page 91.