Write 90 as a product of its prime factors in index form

Can someone me with this problem i don't understand i need

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%

Given sin28.4=.4756, cos28.4=.8796, and tan28.4=.5407 find the cot of 61.6