After 1 year, the bank paid (5.75/4) percent, 4 times.
The value of the investment is (20,000) times (1 + 0.0575/4) to the 4th power.
(1 + 0.0575/4) = 1.014375
That number to the 4th power is 1.05875... (rounded)
The interest alone is (20,000) times (0.05875...) = $1,175.04