3. We look at VARIANCES to gauge our performance. If our overall cost of materials to manufacture 1,000 chairs (our product) was higher than we estimated, then we could safely conclude that: (~seems hard? Not really, set up your own example and see how thing turn out~)

a) The price per unit of raw materials was definitely higher than estimated.

b) The total quantity of raw materials used was definitely more than estimated.

c) Both a and b are true.

d) Either a or b is true, but not both of them.

e) At least a or b is true, or they both could be true. But at least a or b must be true.