What information should be collected from the workers? Bus.

Dog Sex Age Dog Sex Age 1 F 5 9 F 8 2 F 3 10 F 9 3 M 4 11 F 6 4 M 7 12 M 8 5 M 2 13 F 2 6 M 3 14 F 1 7 F 5 15 M 6 8 M 9 16 M 3

a. How would you group the dogs prior to assigning the treatments to obtain a study

having as small an experimental error as possible? List the dogs in each of your groups.

b. Describe your procedure for assigning the treatments to the individual dogs using a

random number generator. Bus. 2.24 Four cake recipes are to be compared for moistness. The researcher will conduct the ex- periment by preparing and then baking the cake. Each preparation of a recipe makes only one cake. All recipes require the same cooking temperature and the same length of cooking time. The oven is large enough that four cakes may be baked during any one baking period, in positions P 1 through P 4 , as shown here. P 1 P 2 P 3 P 4

a. Discuss an appropriate experimental design and randomization procedure if there are

to be r cakes for each recipe.

b. Suppose the experimenter is concerned that significant differences could exist due to

the four baking positions in the oven front vs. back, left side vs. right side. Is your design still appropriate? If not, describe an appropriate design.

c. For the design or designs described in b, suggest modifications if there are five

recipes to be tested but only four cakes may be cooked at any one time. Env. 2.25 A forester wants to estimate the total number of trees on a tree farm that have diameters exceeding 12 inches. A map of the farm is available. Discuss the problem of choosing what to sample and how to select the sample. Engin. 2.26 A safety expert is interested in estimating the proportion of automobile tires with unsafe treads. Should he use individual cars or collections of cars, such as those in parking lots, in his sample? Ag. 2.27 A state department of agriculture wants to estimate the number of acres planted in corn within the state. How might one conduct such a survey? 2.28 Discuss the relative merits of using personal interviews, telephone interviews, and mailed questionnaires as data collection methods for each of the following situations:

a. A television executive wants to estimate the proportion of viewers in the country who

are watching the network at a certain hour.

b. A newspaper editor wants to survey the attitudes of the public toward the type of

news coverage offered by the paper.

c. A city commissioner is interested in determining how homeowners feel about a proposed

zoning change.

d. A county health department wants to estimate the proportion of dogs that have had

rabies shots within the last year. Soc. 2.29 A Yankelovich, Skelly, and White poll taken in the fall of 1984 showed that one-fifth of the 2,207 people surveyed admitted to having cheated on their federal income taxes. Do you think that this fraction is close to the actual proportion who cheated? Why? Discuss the difficulties of obtaining accurate information on a question of this type.