A citrus company is interested in evaluating the performance of two orange juice extractors, A and B. It is believed that both the size and the variety of the fruit yield in the test may influence the yields (percentage juice by weight) obtained from the extractor. Two verities of oranges, Valencia and Navel, in large and small sizes are to be used in the evaluation, The company wants to find the best prediction model relating the mean yield E(y) too the type of orange juice extractor (A or B),. Variety of orange (Valencia or navel) and size of the orange diameter)

A) Identify the independent variables as qualitative or quantitative

B) Write the compete model including all appropriate interactions (Use extractors A on Valencia oranges as the base level)

C) What hypothesis would you test if you wished to determine whether the interacting terms are needed in the model?