# Calculation of Mean & Standard Deviation in STATDISK

Using Statdisk

1. Assume all dice have 6 sides,

a. simulate the rolling of a single die 800 times (select data than dice generator). Use copy/paste to copy the results to the descriptive statistics and histogram modules, and enter results

One Die Mean_____________

Standard Deviation________

Distribution shape_________

b. Part (a) used a single die, but we will now use a pair of dice. Use statdisk to roll two dice 800 times. The 800 values are totals for each pair of dice, so transform the totals to means by dividing each total by 2. (Use Copy/paste to copy the results to the statdisk data window, then use stadisks sample transformations feature to divide each value by 2. To divide each value by 2, select the operation of / and use a constant of 2). Now use copy/paste to copy the

800 means to the Statdisk data window, then use the Descriptive Statistics and histograms modules. Enter the results.

Two Die Mean_____________

Standard Deviation________

Distribution shape_________

c. Repeat part (b) using 10 dice. When finding the mean of the 10 dice, divide each value by 10.

10 Die Mean_____________

Standard Deviation________

Distribution shape_________

d. Repeat part (b) using s20 dice.

20 Die Mean_____________

Standard Deviation________

Distribution shape_________

e. Conclusions

What happens to the mean as the sample size increases from 1 to 2 or 10 to 20?_________________________________________________

What happens to the standard deviation as the sample size increases?

______________________________________________________

What happens to the distribution shape as the sample size increases? __________________________________________________

How do these results illustrate the central limit theorem?_________

___________________________________________

2. Refer to the indicated statdisk data set. In each case, print a histogram, normal quantile plot, and identify outliers.

a. Boston Rainfall: Use the amouns of rainfall in Boston on Fridays.

Outliers_____________

Normal Distribution_______________________________________

b. Cans: Use the axial loads of aluminum cans that are 0.0111 in. thick.

Outliers_____________

Normal Distribution_______________________________________

c. Homeruns: Use the distances of homeruns hit by Mark McGwire in 1998.

Outliers_________________

Normal Distribution_________________________________________

d.. Tax data of Homes:

Outliers____________________

NormalDistribution_______________________________________

#### Solution Summary

Calculation of Mean & Standard Deviation in STATDISK.