Question

Sampling shoppers A marketing consultant observes $50$ consecutive shoppers at a supermarket, recording how much each shopper spends in the store. Explain why it would not be wise to use these data to carry out a significant test about the mean amount spent by all shoppers at this supermarket.

Short answer

The sample is a convenience sample.

Step-by-step solution

Given information

Consecutive shoppers: $50$

Calculation

Because the shoppers were "conveniently" picked as $50$ consecutive shoppers, the sample is a convenience sample. These customers shop on the same day of the week and at the same time of day, implying that we may be excluding a portion of the population.

As a result, the sample is not representative of the entire population.