IT City is a small computer store that sells computers, printers, periphery, and software in the town. It wants to develop a means to forecast its printer sales. The store manager believes that the stores printer sales are directly related to the number of personal computers sold. It has collected the historical data on computer sales and printer sales for the past 6 periods as follows:

Printers Sales	Personal Computer Sales
5	17
12	30
6	12
5	14
8	18
4	10

1. Develop a linear regression model for this data and forecast printer demand if 25 personal computers are sold. (8 marks)
2. Determine the strength of the linear relationship between printer sales and personal computer sales using correlation coefficient (r) and coefficient of determination (r²). Explain the meaning of coefficient of determination (r²). (4 marks)