For each of the following, using the critical value approach, perform the five steps of hypothesis testing. Remember that they could be z- or t-tests. The mean IQ score of students in a school district is reported to be 108. The board of education believes the results of the tests are not accurate, but they aren't sure whether the true result is lower or higher. A random sample of 18 students from a local high school yield a mean IQ score of 102. Assuming that mean IQ scores are normally distributed, and the population standard deviation is 15, determine if the results are statistically significant at =0.05.