1. Using the **elemapi2** data file ( use http://www.ats.ucla.edu/stat/stata/webbooks/reg/elemapi2
) convert the variable **ell** into 2 categories using the
following coding, 0-25 on **ell** becomes 0, and 26-100 on **ell**
becomes 1. Use this recoded version of **ell** to predict **api00**
and interpret the results.

2. Convert the variable **ell** into 3 categories coding those
scoring 0-14 on ell as 1, and those 15/41 as 2 and 42/100 as 3. Do an analysis
predicting **api00** from the **ell** variable
converted to a 1/2/3 variable. Interpret the results.

3. Do a regression analysis predicting **api00** from **yr_rnd**
and the **ell** variable converted to a 0/1 variable. Then create
an interaction term and run the analysis again. Interpret the results of these
analyses.

4. Do a regression analysis predicting **api00** from **ell**
coded as 0/1 (from question 1) and **some_col**, and the
interaction of these two variables. Interpret the results, including showing a
graph of the results.

5. Use the variable **ell** converted into 3 categories (from
question 2) and predict api00 from **ell** in 3 categories, from **some_col**
and the interaction. of these two variables. Interpret the results, including
showing a graph.