(a) A consultant wants to ask workers at a factory about the workers' job satisfaction. Which of the following best describes arandom sampleof workers?

• The consultant assigns each worker a different number. Using a random number table, he draws50of those numbers at random. Then, the consultant selects the workers assigned to the drawn numbers. Every set of50 workers is equally likely to be drawn using the random number table.
• The consultant forms2 groups of workers based on the workers' shifts. Then, he selects25 workers at random from each group.
• All of the workers on the second floor of the factory building are easily accessible. So, the consultant selects the first50 workers from the second floor to arrive at work on a particular day.

(b) A manager at a bus company wants to survey employees about the new uniforms. Which of the following best describes acluster sampleof employees?

• The manager forms groups of9 employees based on the departments the employees are in. Then, she selects all of the employees in6 randomly chosen groups.
• The manager uses a computer program to draw54 employees at random and selects these employees. Every set of54 employees is equally likely to be drawn by the computer program.
• The manager takes a list of the employees and selects every6th employee until54employees are selected.

(c)A bank analyst wants to ask customers who have a mortgage with the bank about the customers' home-buying experiences. Which of the following best describes astratified sampleof customers?

• The analyst forms groups of8 customers based on the cities the customers live in. Then, she selects all of the customers in7 randomly chosen groups.
• The analyst takes a list of the customers and selects every7th customer until56customers are selected.
• The analyst forms7groups of customers based on the customers' mortgage amounts. Then, she selects8customers at random from each group.