Answer:
Assuming that the T-bill's face value is $10,000
n = 160 days
discount rate = 0.421%
we can use the following formula to determine the market value:
market price of the T-bill = face value - (discount rate x days until maturity/360 days x face value)
market price of the T-bill = $10,000 - (0.421% x 160/360 x $10,000) = $10,000 - $18.71 = $9,981.29