a) A professor has been teaching statistics for many years. His records show that the overall mean for the final exam scores is 82 with a standard deviation of 10. The professor believes that this year's class is superior to his previous ones. The mean for final exam scores for this year's class of 65 students is 87. 1. Would you use a one or two tailed test? Why? 2. What are the null and alternative hypothesis 3. What is the standard error or the mean? 4. What is the Zobt? 5. What is Zcrit? 6. What is your conclusion? b) A school psychologist want to know if head start programs change students' IQ scores. The population mean is 100 and the population standard deviation is 15. After a year in the program, the sample mean IQ for students in Head Start is 103 and there are 120 participants. 1. Would you use a one or two tailed test? Why? 2. What are the null and alternative hypothesis 3. What is the standard error or the mean? 4. What is the Zobt? 5. What is Zcrit? 6. What is your conclusion?