What mean:

a) Different sample designs use different amounts of information available in the selection. For each of the OSU sample designs, strategic selection and systematic selection, indicate which additional information is used, how it is used and why it is used.

b) Name two estimation techniques that use additional information when estimating a population mean. Also describe how the extra information is used and why it is used.

c) Explain what over-coverage and under-coverage are and what effects it may have when estimating a population mean