For continuously compounded interest:
Amount = Principle * e^(rate*time)
A = Pe^(rt)
Principle = 1300
Rate of 4.2% converted to decimal value: r=0.042
(Move decimal two places)
Time 5years 9months converted to years: 5.75
(9 months / 12 months = 0.75)
Plug in the values,
Amount = 1300 * e^(0.042 * 5.75)
And let your calculator do the rest.