# Homework Assignment for Lesson 0

### Homework Assignment

Consider the following soap experiment, run as a class project by Suyapa Silvia in 1985. The purpose of this experiment is to compare the extent to which three particular types of soap dissolve in water. It is expected that the experiment will answer the following questions: Are there any differences in weight loss due to dissolution among the three soaps when allowed to soak in water for the same length of time? What are these differences?

Four cubes of three different types of soap (Regular, Deodorant, and Moisturizing) were weighed and then placed in baking pans filled with water kept at room temperature. After sitting in the water for 24 hours, the cubes of soap were weighed again. The difference in weights (weight after minus weight before) of the twelve cubes of soap are shown in the table below:

 Cube Regular Deodorant Moisturizing 1 -0.30 2.63 1.86 2 -0.10 2.61 2.03 3 -0.14 2.41 2.26 4 0.40 3.15 1.82

Do the following. Turn in your completed homework as a Word or PDF document. Include all SAS code used, and clearly label which SAS code corresponds to which problem. Make your final report clean and clear. Don't just slap your answers and code together. Take the time to write a sentence or two describing how everything comes together.

1. Input the soap experiment data into SAS. Format the data when you enter it so that there are two columns, one for the type of soap and another for the weight lost in the experiment. Each row of your data object should correspond to a single bar of soap (a single experimental unit).
2. Convert the measurements of weight lost to kilograms.
3. Report the mean and standard deviation of the observed weight lost (in kilograms).
4. Plot a histogram of all of the observations from the experiment (in kilograms).
5. Plot side-by-side boxplots of the weight lost (in kilograms), with one boxplot for each type of soap.
6. Comment on any observed differences between the soap types that you think would be worth investigating further.