The Wall Street Journal contained a table showing yield comparisons for groups of corporate bonds. The following data have been adapted from the table:

   

Yield

Percentage

   

As of

52-week

 
 

28-Apr

27-Apr

High

 

Risk category

     

1-10 year maturities:

 

Low

High quality

7.08%

6.94%

7.16%

5.32%

Medium quality

7.41

7.26

7.49

5.76

Over 10 year maturities:

   

High quality

7.91

7.81

8.06

6.93

Medium quality

8.36

8.25

8.49

7.29

High-yield bonds

10.45

10.48

10.53

9.25

Standard & Poor”s

ratings were:

High quality

AAA to AA

Medium quality

A to BBB

High yield

BB to C

Prepare written answers to the following questions.

a. In each column of numbers, why do the yield rates increase from top to bottom?

b. For the high quality and medium quality bonds, what could account for the increase in the yield rates from 4/27 to 4/28? Take into consideration possible economic events.

c. Which risk class of bonds was closest to its 52-week high on 4/28? What could have been the cause?