How do you answer this

()1. how do you find range? 2.the following set of data is to be organized into a histogram. if there are to be five intervals on the graph, what should the length of each interval be? 30, 34, 23, 21, 27, 25, 29, 29, 25, 23, 32, 31

Asocial networking site currently has 400,000 active members, and that figure is predicted to increase by 32% each year. the following expression represents the number of active members on the site after t years.

Two planes leave an airport at the same time, one flying east, the other flying west. the eastbound plane travels 20 mph slower. they are 1600 mi apart after 2 hr. find the speed of each plane.