Describe and correct the error a student made when responding to the following question. A website to post a blog about the most popular type of pet in the Seattle area. Would a sample consisting of every tenth ticket holding to the local dog show be representative? Explain. Student Yes, since the sample is systematic random sample, it would be representative of the population.

The student is correct in saying that "systematic random sample" is applied, since the rule is "select every 10th ticket". However, this does not represent the population because those who attend a dog show are very likely to be dog lovers. This leaves out cat lovers or any other type of pet. It may be possible that someone is a cat lover but they're at the dog show (due to their spouse pulling them along), but it's probably not that common. We say that people who pick dogs as their favorite would be over-represented, while any other pet would be under-represented if they were represented at all.

A better way to get a sample would be to go to a pet store and have every 10th purchase be selected for a survey. To entice customers to participate in the survey, it would be helpful to offer a discount, free product, or a chance to win a prize. Otherwise, the customer may ignore the survey and that could likely lead to bias.

x intercept = (-1,0)   (4,0)