U.S. Trea- sury bill futures contract began trading on June 19, 2001 and expires on March 18, 2002. On December 19, 2001, the index price was 98.230, which is labeled as "Contract Price" and is located on the left-hand side of the screen. The yield on a bank discount basis for this Treasury bill futures contract is:       Yd = -1---0---0-----------9---8---.--2---3----0-- 100 = 0.0177 or 1.77%     The invoice price that the buyer of $1 million face value of 13-week Treasury bills must pay at settlement is found by first computing the dollar discount, as follows:   D = Yd´ $1,000,000 ´ t /360   where t is either 90 or 91 days. Typically, the number of days to maturity of a 13-week Treasury bill is 91 days. The invoice price is then:   Invoice price = $1,000,000 - D   For example, if the index price is 98.230 (and a yield on a bank dis- count basis of 1.77%), the dollar discount for the 13-week Treasury bill to be delivered with 91 days to maturity is:   D = 0.0177 ´ $1,000,000 ´ 91/360 = $4,474.167       The invoice price is:   Invoice price = $1,000,000 - $4,474.167 = $995,525.833   The minimum index price fluctuation or "tick" for this futures con- tract is 0.005. A change of 0.005 for the minimum index price translates into a change in the yield on a bank discount basis of one-half of a basis point (0.00005). A one-half basis point change results in a change in the invoice price as follows:   0.00005 ´ $1,000,000 ´ t/360