Question 1
A local consumer reporter wants to compare the average costs of grocery items purchased at three different supermarkets, A, B, and C. Prices (in dollars) were recorded for a sample of 60 randomly selected grocery items at each of the three supermarkets. In order to reduce item-to-item variation, the prices were recorded for each item on the same day at each supermarket.
Identify the blocks for this experiment.
◦ the day on which the data were collected
◦ the 60 × 3 = 180 prices
◦ the three supermarkets
◦ the 60 grocery items
Question 2
True or False.
When a variable is identified as reducing variation in the response variable, but no additional knowledge concerning the variable is desired, it should be used as the blocking factor in the randomized block design.
◦ True
◦ False
A plant response to flooding.
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