Harmonic Motion and Sinusoidal Function Problem....

I have a huge math portfolio due tomorrow, and I could really use someone's help figuring out my last problem.

Thanks!

Suppose the length of time between two consecutive high tides is approximately 12.1 hours. According to NOAA on June 28, 1997 in Juneau, Alaska, high tide occurred at 8:11 AM (8.1833 hours) and low tide occurred at 2:14 PM (14.2333 hours). The height of the water at high tide was 13.2 feet and the height of the water at low tide was 2.2 feet.

a) Find a sinusoidal function in the form y=AsinB(x+C)+D for the situation.

b) Approximately when will the next high tide occur?