4. The 10 most active stocks on the New York Stock Exchange on March 6, 2006, are shown here (The Wall Street Journal, March 7, 2006).

AT&T Lucent Nortel Qwest Bell South Pfizer Texas Instruments Gen. Elect. iShrMSJpn LSI Logic Exchange authorities decided to investigate trading practices using a sample of three of these stocks.

a. Beginning with the first random digit in column 6 of Table 7.1, read down the column to select a simple random sample of three stocks for the exchange authorities.

b. Using the information in the first Note and Comment, determine how many different simple random samples of size 3 can be selected from the list of 10 stocks.