(a) Give five (5) reasons why researchers' sample when conducting research
(b) In a random sample of 100 MBA females, an average of 58 use their seatbelt regularly with a standard deviation of 30
(i) Compute 95% and 99% confidence intervals for the mean MBA females who always wear their seatbelt 

(ii) Is there evidence that the mean of all MBA females who always wear their seatbelt is different from 65

(iii) Identify three (3) factors affecting Interval Width (Precision). 

(c) Explain the statistical relationship between the sample size and standard error
(ii) The annual starting salary for newly employed graduates with Business Administration degrees are believed to have a standard deviation of approximately GHS 2000. Assume that a 99% confidence interval estimate for the mean annual starting salary is desired. How large a sample should be taken if the margin error 
(a) GHS 
(b) GHS 
(c) GHS 1007 Comment on your results.