Make sure your calculator is set to DEGREES and not RADIANS when performing your sinθ calculation.
sin(10) = -0.54402
sin(10°) = 0.17365
You could also try using trig tables if you're unsure how to do this.
So:
2500sin(10°) = 434 lb
So if 24 people chose popcorn and there is a total of 60 people surveyed, the fraction would be 24/60. You still need to simplify the fraction, so divide 24/60 by 4 to get 6/15. Hope this helps. -S