a. A set of data is at the nominal level of measurement and you want to obtain a representative data value. Which of the following is most appropriate: mean, median, mode, or midrange? Why?

b. A sample is obtained by telephoning the first 250 people listed in the local telephone directory. What type of sampling is being used (random, stratified, systematic, cluster, convenience)?

c. An exit poll is conducted by surveying everyone who leaves the polling booth at 50 randomly selected election precincts. What type of sampling is being used (random, stratified, systematic, cluster, convenience)?

d. A manufacturer makes refill cartridges for computer printers. A manager finds that the amounts of ink placed in the receptacles is not very consistent, so that some cartridges last longer than expected, but others run out too soon. She wants to improve quality by making the cartridges more consistent. When analyzing the amounts of ink, which of the following statistics is most relevant: mean, median, mode, midrange, standard deviation, first quartile, third quartile? Should the value of that statistic be raised, lowered, or left unchanged?