Which of these is correct and why?

Find the value of x in each case. give reasons to justify your solutions! d q ∈ pr

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.

Divide reduce the answer to lowest term 3/7 divided 1 1/6