Question: This is also Exercise. A popular Sunday newspaper magazine often includes a yes-or-no survey question such as "Do you think there is too much violence on television?" or "Do you think parents should use physical discipline?" Readers are asked to phone their answers to the magazine, and the results are reported in a subsequent issue.

a. What is this type of sample called?

b. Do you think the results of these polls represent the opinions of all readers of the magazine? Explain.

Exercise: A popular Sunday newspaper magazine often includes a yes-or-no survey question such as "Do you think there is too much violence on television?" or "Do you think parents should use physical discipline?" Readers are asked to mail their answers to the magazine, and the results are reported in a subsequent issue.

a. What is this type of sample called?

b. Do you think the results of these polls represent the opinions of all readers of the magazine? Explain.