A Typical IQ test has a population mean of 100 and a standard deviation of 15. Answer the following based on the above mean and standard deviation:

1. If Mark had an IQ of 110, what would be his z, or standard score? 

2. What proportion of the population would have a score equal to or higher than Mark? 

3. Andrew took the same test and got a 95. What is Andrew’s Z score? 

4. What proportion of the population would have IQ’s equal to or between Mark and Andrew? 

5. Approximately 84% of IQ scores would be equal to or between what two scores? 

6. If a researcher took a sample of 25 people, what would be the standard error? 

7. Based on this standard error, what is the probability that the mean of a sample of 25 peope would be greater than 115? 

8. What is the probability that the mean of a sample of 50 people would be greater than 115?