Question: You hear a claim by the mayor about the average IQ score of a resident in your home town. He claims that the average IQ has increased over the past two years. From past data, you had always believed the average IQ score to be 117. To validate his claim, you decide to take a sample of 300 people to complete an IQ test. Your sample average is 122 with a standard deviation of 4. At a 95% confidence level, do you believe his claim?