Question 5

A research student wants to compare the average intelligence level of students of from a certain primary school in Nairobi county using standardized IQ test which has a population mean (u) of 100 and a standard deviation () of 16. A sample of 50 students scored an average of 105 in the IQ test. Does this value differ from 100? Use a=0.01 for this test

a) What is the appropriate test? Explain (3 marks)

b) Develop the null and alternative hypotheses, paying attention to whether this is a one tailed or two tailed test (4 marks)

c) Find the significance levels and corresponding critical values (3 marks)

d) Compute the appropriate test (6 marks)

e) Make a decision based on your results in (d) above and write a brief summary of the results (5 marks) f) Determine a 95% and 99% confidence interval for the mean IQ level in these population of students (4