Chapter 2 Exercises

1. It has been found that there is a positive association between the number of fire fighters battling a blaze and the damage done. The more fire fighters, the greater the dollar damage.

Does this mean that having a larger number of fire fighters results in careless or reckless work?

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2. Comment on the following situations:

• A stockbroker claims that because 85% of his recommendations last year performed better than market expectations (appropriately defined) everyone should invest with him.
• A fertilizer company conducted a study that showed that farmers who use Moregro fertilizer last year experienced a 10% increase in crop yield over the preceding year. This company is now advertising that Moregro will increase crop yields by 10%.

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3. Comment on the following conclusion:

In the US in 1985, 19,893 people were murdered, compared to 16,848 in 1970 - nearly a 20% increase. These figures show that the US became a more violent society over the period 1970-1985.

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4. As a method for collecting survey data identify the principal advantages and disadvantages of the

• personal interview
• telephone interview
• written questionnaire

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5. Refer to the Introduction for the context of this question. What kinds of studies were:

• the Pareto analysis of types of damage to cartons,
• carton damage before and after the younger operators received extra training, and
• carton damage after clamps were replaced on loaders.

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