Amanufacturer of cellular phones has decided that an assembly line is operating satisfactorily if less than 6% of the phones manufactured per day are defective. to check the quality of a day's production, the company decides to randomly sample 30 phones from a day's production and test for defects. define the population of interest to the manufacturer.
a. all the phones produced during the day in question.
b. the 30 phones sampled and tested.
c. the 30 responses: defective or not defective.
d. the 3% of the phones that are defective.

a) All the phones produced during the day in question.

Step-by-step explanation:

In statistics, the Population is all the objects with the same characteristics in which we have an interest in doing an experiment or statistical analysis. Sometimes to make it more simple, we take just a sample of the population and we do the experiments with them, and then the answers are used to all of the objects.

In this case, they want to analyze all the cellphones but they only take a few to do it. So the answer is a) All the phones produced during the day in question.