When christopher was on his trip, the exchange rate for us dollars to singapore dollars was 1:1.3914, and the exchange rate for singapore dollars to australian dollars was 1:0.7786. how much did christopher spend in total, measured in us dollars? round all currency values to two decimal places. a. $1,517.89 b. $1,526.19 c. $1,809.35 d. $2,776.72