The mean IQ score for 1600 students is 90, with a standard deviation of 15. Assuming the scores have a normal curve, answer the following. a. How many have an IQ score between 75 and 105? b. How many have an IQ score between 60 and 120? c. How many have an IQ score over 135? a. The number of students with an IQ score between 75 and 105 is (Round to the nearest person as needed.) b. The number of students with an IQ score between 60 and 120 is (Round to the nearest person as needed.) c. The number of students with an IQ score over 135 is (Round to the nearest person as needed.)