# IAT432 – Statistics Exercise

The study is looking at the difference between an alphabetic keyboard and a phone pad keyboard.

• Independent variable: mouseboard layout (either Phonepad or Alphabetic)
• Dependent variables:
• typing speed in char/minute
• number of errors

You’ll need a copy of this Excel data file. Note that the file contains TWO data sets: One on sheet 1 (Part A) and one on sheet 2 (Part B).

Also, your copy of Excel needs to have the Data Analysis Toolpak installed (for older versions of Excel) or the Solver analysis package installed (for newer versions of Excel). Instructions for how to get it are here for Mac or PC.

Instructions on how to use the t.test function in Excel are here.

What to do:

1. Plot frequency distributions for values from Phone Pad and Alphabetic for each of the dependent variables (i) typing speed and (ii) number of errors – for both data sets (Part A, Part B).

You should plot both Phone Pad and Alphabetic results for each dependent variable so you can compare the two plots. This means you should have two graphs (Typing Speed and # of Errors) with two distributions (Phonepad, Alpha) on each graph for Part A, and two graphs with two distributions on each graph for Part B.

2. Calculate mean, median and mode for the Phonepad and Alphabetic layouts for each dependent variable (i) typing speed (ii) number of errors.

3. Calculate standard deviation for each distribution.

4. Calculate t-test for each pair of means.