200 students are enrolled in a first year statistics course. Two options are offered: the students may either attend regular lectures or they may take a reading-based learning program. 130 of the students say they prefer lectures, the other 70 say they prefer reading-based learning. The course coordinator wants to test two hypotheses:

i) Students perform better in the final exam if they use the reading-based option.

ii) Students perform better in the final exam if they use their preferred method of instruction.

(a) What are the two explanatory variables in this study?

(b) What is the response variable?

(c) How many combinations of the explanatory variables are possible? List these.

(d) Design an experiment to test the two hypotheses. Comment on control, randomisation and replication in your design. Use a schematic diagram or flow chart to illustrate your experiment.