Problem
Advertising has been long seen as an effective means for sales promotion. The boss of a record company was also interested in predicting the album sales from advertising. He believed that the total album sales in the form of either CDs or Downloads after release (defined in a variable with the name of Sales) can be predicted by the amount of money spent in promoting the album before release (defined in a variable with the name of Adverts) and the number of plays on the radio per week (defined in a variable with the name of Airplay). If true, the company plans to promote the album sales through reasonable allocation of resources accordingly. To test this, market researchers sampled 200 different album releases and then collected data. Data analysis is conducted in SPSS to support the decision making of this record company.
a) Sales: the total album sales (in 1,000 units)
b) Adverts: the amount of money (in 1,000 £s) spent in promoting the album
c) Airplay: the number of plays on the radio
Imagining you are the market researcher in the case, will you use a sample or a census?
Discuss the conditions/situations when a sample is preferable to a census and a census preferable to a sample.