The CEO of a major bank wanted to assess how many of the bank’s customers are satisfied, so he decided to conduct a small survey. At the time of the survey, the bank had several millions of customers across 300 bank branches of varying sizes. For each of the 300 branches, he picked one of the branch's customers randomly and surveyed him.

What type of statistical study did the CEO use?

Choose 1

Choose 1

(Choice A)

A

Sample study

(Choice B)

B

Experiment

(Choice C)

C

Observational study

Is the study appropriate for the statistical questions it's supposed to answer?

Mark the most suitable choice.

Choose 1

Choose 1

(Choice A)

A

Yes, because the sample was big enough and obtained in an appropriate manner.

(Choice B)

B

No, because the randomization of the sampling was flawed.

(Choice C)

C

No, because the study didn't have a control group and a treatment group.

(Choice D)

D

No, because the type of study chosen is inappropriate.