A consultant wants to ask workers at a factory about the workers' job satisfaction. Which of the following best describes a cluster sample of workers? a. The consultant takes a list of the workers and selects every 6" worker until 60 workers are selected.
b. The consultant forms 5 groups of workers based on the workers' shifts. Then, he selects 12 workers at random from each group.
c. The consultant forms groups of 12 workers based on the lengths of time the workers have worked at the factory. Then, he randomly chooses 5 groups and selects all of the workers in these groups

i think option c must be correct because it has formed the grops on the basis of length of time and made the group by random selection.

a complex number is a number that can be expressed in the form a + bi, where a and b are real numbers, and i is a solution of the equation x2 = −1. because no real number satisfies this equation, i is called an imaginary number. has no real solution, since the square of a real number cannot be negative.

typically if you want , you would actually put questions here for us to you. but hey, that's just me. maybe someone will magically answer the questions for you without knowing what they are.