A psychology professor theorizes that children will score differently on an IQ test depending on what type of music they are exposed to during the test. She randomly divides 18 students into three groups of 6 children each. Those in group A are exposed to classical music. Those in group B must listen to jazz music. And those in group C are exposed to heavy metal music. Here are the results of their IQ tests.

IQ tests of IQ tests of IQ tests of children in children in children in group A group B group C 111 105 142 115 109 132 108 110 110 102 110 105 124 125 87 165 135 150