I need 11 through 13

Factor the polynomial. b^2 + 4b + 4

Astudent showed the steps below while solving the inequality |x-4|< 1 by graphing.

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.