Roy's toys received a shipment of 100,000 rubber duckies from the factory. the factory couldn't promise that all rubber duckies are in perfect form, but they promised that the percentage of defective toys won't exceed 5\%5%. roy wanted to get an estimation of the percentage of defective toys, and since he couldn't go over the entire 100{,}000100,000 duckies, he took a random sample of 10 duckies. he found that 10% of them were defective. what type of statistical study did roy use?

Observational study

Step-by-step explanation:

There are three types of statistical study:

1) Experimental study: Under this study, an experiment is done and then the results are recorded.

2) Observational study : Under this study, events are observed and the results are recorded.

3) Survey: Under this study, a survey is carried out and the results are recorded.

Here, its not possible for Roy to check each and every toy if it is defective or not. So he took a sample and found that 10% were defective. He has carried an observational study.

its a straight line parallel to the time axis

answer: your correct answer is b. d.

step-by-step explanation: