The heights of american men aged 18 to 24 are approximately normally distributed with a mean of 68 inches and standard deviation of 2.5 inches. half of all young men are shorter than?
how do i figure this

One cell phone plan charges $20 per month plus $0.15 per minute used. a second cell phone plan charges $35 per month plus $0.10 per minute used. write and solve an equation to find the number of minutes you must talk to have the same cost for both calling plans.