These are the sample solutions for
problems <a href="selected_soln1.pdf"> 7.18 and 7.19</a>. 
Note that there are several small discrepencies (like the problem numbers(
6.20 and 6.21 respectively), and Robert F. Scott's datte of birth (Q7.19(a))) between the supplied solutions
and the actual questions in your textbook. 
Most of you did fine on 7.1 and 7.27. If you have any questions on these
two questions please see me. <BR>
<STRONG> Please report any problems to me.