A manager at a bus company wants to survey employees about the new uniforms. Which of the following best describes a stratified sample of employees? a. The manager uses a computer program to draw 78 employees at random and selects these employees. Every set of 78 employees is equally likely to be drawn by the computer program.
b. The manager forms 6 groups of employees based on the departments the employees are in. Then, she selects 13 employees at random from each group.
c. The manager asks for volunteers and selects every volunteer until 78 employees are selected. She selects the volunteers because these employees are easily accessible.