Answer:
Missing word "a. What must the six-month risk-free rate be in Japan"
a. Spot rate = 1 US $ = 1.2377 Aus.dollar
Forward rate = 1 US $ = 1.2356 Aus.dollar
1.2356 = (1 + i Ad)
1.2377 (1 + 0.05)
0.9983 * (1.05) = 1 + i.Ad
1.048215 = 1 + i.Ad
i.Ad = 1.048215 - 1
i.Ad = 0.048215
i.Ad = 4.82%
b. Spot rate = 1 US $ = 100.3300 Japan Yen
Forward rate = 1 US $ = 100.0500 Japan Yen
100.0500 = (1 + i Ad)
100.3300 (1 + 0.05)
0.9972 * (1.05) = 1 + i.Ad
1.04706 = 1 + i.Ad
i.Ad = 1.04706 - 1
i.Ad = 0.04706
i.Ad = 4.71%