Purpose: The purpose of this lab is to get some practice downloading and handling some data. No deep concepts here, just some practical experience.

Advice: This is not an Excel tutorial. Youíll need to teach yourself Excel. (Or you can use another package, but you had better be certain it can do what it needs to do for this course.) You can get help for Excel either from the Science Learning Center assistant, the Excel Handbook that is a recommended text for this course, from the TA, or from me. I've found that the Excel Handbook frequently gives bad advice, but this might be more because of changes in new versions of Excel.

Data: Weíll use the "Cheese" data set, which is described on page D-1 in the appendix of your textbook. You can find the data themselves on the CD that came with the book. On my CD (the Mac version) it was under Extras: Macintosh Data Sets: Appendix. You can also find it online at http://www.stat.ucla.edu/data/moore/

Activity:

1. Download the Cheese data into an Excel Workbook. (The command for this is under File: Open). Follow the steps recommended in the "TextWizard". (Unless something went wrong, just accept all of its choices.)
2. Make a histogram of the variable "Taste". In words, describe the shape of the histogram.
3. Make a scatterplot showing Taste (the second column of data) on the vertical axis and Acetic (the third column) on the horizontal axis. Does is look like there is a relation between the two? If so, what kind?

To make a histogram, you need to use the Data Analysis Tools. To see if you have this, go to Add-ons underneath the Tools menu, and click on the box to turn it on.

Excel is tricky (at least on my computer) when it comes to using the Data Analysis Tools. While it easily does numerical calculations, it won't put histograms in the same workbook as the the data. You'll have to choose the "New Workbook" option. This is irritating, because you'll have to create a new workbook for each histogram. Let me know if you figure out a way around this. (And it might not be a problem on PCs.)

To "clean up" your histogram, you need to click one on the chart, and then once on one of the bars. Then choose "Format: Selected Data Series" . A pop-up menu will appear. Select Options, and change the Gap Width to 0. You can also label your axes and clean up other stuff here as you please.

When you make scatterplots, you'll find that the left-most column is the default x-axis, (horizontal) and the other column the y-axis. Two switch them, you need to choose "Series" on the second page of the Chart Wizard, and switch the labels for the x and y axes. Afterwards, you'll need to rescale your graph. To do this, click once on the x axis and select Selected Axis under the Format menu. Go to scale and change the minimum and maximum values accordingly.