The senior class is making T-shirts as a fundraiser. The material needed to make each T-shirt costs $3.75. The students sell each shirt for $10.To increase sales, the students spend $350 on advertising. How many t-shirts must the students sell to breakeven? PLEASE HELP! I need to show work

Assume that adults have iq scores that are normally distributed with a mean of mu equals 100 and a standard deviation sigma equals 20. find the probability that a randomly selected adult has an iq between 80 and 120.assume that adults have iq scores that are normally distributed with a mean of mu equals 100 and a standard deviation sigma equals 20. find the probability that a randomly selected adult has an iq between 80 and 120.