If 0 is the radian measure of a central angle of a circle and r is the radius of the circle, which is the correct derivation of the area, A, of the sector bounded by the sides of the central angle and the arc it subtends?

In a certain city, the hourly wage of workers on temporary employment contracts is normally distributed. the mean is $15 and the standard deviation is $3. what percentage of temporary workers earn less than $12 per hour? a. 6% b. 16% c. 26% d. 36%