1. Use Calc > Make Patterened Data > Simple Set of Numbers to enter numbers from -3 to 3 by increments of 0.05 into C1.
2. Graph the probability density curves for the following distributions: a. N(0,1); b. Uniform(-3, 3); c. t(1); d. t(40).
A. The first step is to find the heights of the density curves. You can do this by selecting Calc > Probability Distributions and then the appropriate distribution. Make sure you use the probability density option.
B. Construct the plots by selecting Graph > Scatterplot.
C. Compare and contrast the four density curves.
3. Use simulation to develop your understanding of normal probability plots.
A. Select Calc > Random Data and then the appropriate distribution to generate 100 random observations from the following distributions: a. N(0,1); b. Uniform(-3, 3); c. t(1); d. t(40).
B. Construct Normal Probability Plots for each of the four sets of random data above.
Select Graph > Probability Plot to construct the normal probability plot.
OR
Select Calc > Calculator to create the normal scores for C1 and store them in C2. Then plot C2 versus C1 using Graph > Scatterplot.
C. Describe each of the plots. Are the differences in the density curves appearing on the normal probability plots? If so, please explain how.
4. Use appropriate methods for assessing normality to see if the normal distribution would be an appropriate for the quantitative variables from our first class meeting (p:\data\math\stats\Day1 S2013.mtw).