The amount of time a Lakemore Statistics student spends on homework each evening is approximately normally distributed. If 22% of the 75 students spend at least 47 minutes doing homework, and Shelby, who spends 65 minutes has a standardized score of 1.932, determine:

a) the mean and standard deviation of the distribution

b) the approximate number of students who spend less than 15 minutes on homework

I have no idea what to do! Please help!:confused: