XrA14-18 Billions of dollars are spent annually by Americans for the care and feeding of pets. A survey conducted by the American Veterinary Medical Association drew a random sample of 1,328 American households and asked whether they owned a pet and, if so, the type of animal. In addition, each was asked to report the veterinary expenditures for the previous 12 months. Column 1 contains the expenditures for dogs, and column 2 stores the expenditures for cats. The results are that 474 households reported that they owned at least one dog and 419 owned at least one cat. The latest census indicates that there are 112 million households in the United States. (Source: Statistical Abstract of the United States, 2006, Table 1232.)

a. Estimate with 95% confidence the total number of households owning at least one dog.

b. Repeat part

(a) for cats.

c. Assume that there are 40 million households with at least one dog and estimate with 95%

confidence the total amount spent on veterinary expenditures for dogs.

d. Assume that there are 35 million households with at least one cat and estimate with 95%

confidence the total amount spent on veterinary expenditures for cats.