Identify the type of sampling (random, systematic, convenience, stratified, cluster) used when a sample of the 637,133 stockholders is obtained as described. Then determine whether the sampling scheme is likely to result in a sample that is representative of the population of all 637,133 stockholders.

a. A complete list of all stockholders is compiled and every 500th name is selected.

b. At the annual stockholders’ meeting, a survey is conducted of all who attend.

c. Fifty different stockbrokers are randomly selected, and a survey is made of all their clients who own shares of IBM.

d. A computer file of all IBM stockholders is compiled so that they are all numbered consecutively, then random numbers generated by computer are used to select the sample of stockholders.

e. All of the stockholder zip codes are collected, and 5 stockholders are randomly selected from each zip code.