The equation sin(40°) = B/20 can be used to determine the length of line segment AC. what is the length of AC round to the nearest tenth. please help

4. jake needs to score in the top 10% in order to earn a physical fitness certificate. the class mean is 78 and the standard deviation is 5.5. what raw score does he need? z value for top 10% =1.282 how do i get the z value? what is the equation for this? raw score =mean+z*sd = 78+1.282*5.5 = 85.051