Solve!(i have answers but need help to solve each)

The number of chocolate chips in a bag of chocolate chip cookies is approximately normally distributed with a mean of 12611261 chips and a standard deviation of 118118 chips. (a) determine the 2626th percentile for the number of chocolate chips in a bag. (b) determine the number of chocolate chips in a bag that make up the middle 9696% of bags. (c) what is the interquartile range of the number of chocolate chips in a bag of chocolate chip cookies?

An expression for the average of x 2x and 3y

Hdtv screens usually have a width-to -height ratio of 16: 9. which screen dimensions are in the same proportion?