I realised I should post this here instead of in the pre-uni section:


Please tell me what it wants from me!! (hehe - it's a vague question in my opinion) :

The quality of photographs taken are being judged as a function of the camera (X1), film (X2), and the presence or absence of a flash (X3). The data are as follows:

Run # X1 X2 X3 Quality (y)
1 - - - 81
2 + - - 84
3 - + - 75
4 + + - 68
5 - - + 92
6 + - + 83
7 - + + 72
8 + + + 91

a) Analyze the data using only the main effects in a linear model.

b) Test each of the main effects for significance. Which of these effects is of greatest importance?

Err... 'scuse me? What is it asking? Do a regression? Find coefficients? Any idea? Thanks a bunch!