Answer:
61.512
Step-by-step explanation:
Put 14 where x is and do the arithmetic. Arguments for trig functions are always radians unless otherwise specified.
y =18.614 sin(0.521x - 1.984) + 76.900
y =18.614 sin(0.521·14 - 1.984) + 76.900 = 18.614sin(5.31) +76.900
y ≈ 18.614·(-0.82668) +76.900 = -15.388 +76.900
y ≈ 61.512
The regression model predicts y(14) = 61.512.