7.1 Place the code from the Bisection Root Finder case study into a SAS/IML module, say BiRoot.  This module should solve for the square root of an arbitrary value x where the initial interval endpoints (lo and hi) and the convergence criterion (delta) are inputs for this module.  Build in checks to make sure the lo and hi values are correctly specified (what does this mean? can you do something sensible if lo-hi are poorly specified?) and that x is positive.    Present at least 4 test cases to show this works.

7.2  Write a module that generates a percentile-based bootstrap confidence interval for the mean (input:  vector x and the confidence level).  Import the Weight variable data from SASHELP.CARS into IML to illustrate your module.