Title: population_bias_and_sampling
Course: quiz duplicate error

Q: As part of a project for math class, Peter randomly interviewed 51 teenagers at a park to determine their favorite park activity. Based on the results of his survey, he made the following claim:
One out of four park-goers like to hike on the trails.
Explain why this is not a valid claim.
- Only people on the trails were surveyed.
- Not enough teenagers at the park were surveyed.
- Peter only interviewed teenagers at the park, but made the claim about all park-goers.
- The teenagers were not randomly interviewed.
A: Peter only interviewed teenagers at the park, but made the claim about all park-goers.
If right: Since Peter only surveyed teenagers at the park, his sample is not representative of all park goers. It is invalid to make a claim about the entire population when a biased sample was used to conduct the survey.
If wrong: Since Peter only surveyed teenagers at the park, his sample is not representative of all park goers. It is invalid to make a claim about the entire population when a biased sample was used to conduct the survey.

Q: Bill wanted to know how many times students at his middle school go to the beach each week during the summer. He surveyed every other middle school student at the mall last Saturday. After analyzing the data collected, Bill determined that the average student from his middle school goes to the beach about 2.4 times a week during the summer. What error did he make in the survey?
- The sample probably contained students from other schools.
- High school students should have been included in the sample.
- The sample should have included teachers as well as students.
- The sample should have included students from other schools.
A: The sample probably contained students from other schools.
If right: Since Bill surveyed every other middle school student at the mall last Saturday, the sample probably contained students from other schools.
If wrong: Since Bill surveyed every other middle school student at the mall last Saturday, the sample probably contained students from other schools.

Q: Is the sample described a good sample? Explain.

To find the average age of drivers in a particular city, use all the names of people with driver’s licenses put into a file. One hundred names are picked blindly from the file as a sample.
- No; the sample is not selected from the population to be studied.
- No; the sample is not random.
- Yes; the sample is selected at random from the population to be studied.
A: Yes; the sample is selected at random from the population to be studied.

Q: Is the sample described a good sample? Explain.

To find the average income of an adult in the United States, 250 workers in Tennessee are questioned.
- No; the sample is not random.
- Yes; the sample is selected at random from the population to be studied.
- No; the sample is not selected from the population to be studied.
A: No; the sample is not random.

Q: Is the sample described a good sample? Explain.

To find the average number of shoppers in a particular store, shoppers are counted on two consecutive Saturday mornings.
- No; the sample is not selected from the population to be studied.
- No; the sample is not random.
- Yes; the sample is selected at random from the population to be studied.
A: No; the sample is not random.

Q: Is the sample described a good sample? Explain.

You want to find out the favorite subjects of students at your school. Which plan describes a good sample?
- Interview a group of students on their way to the library.
- Interview students leaving a classroom.
- Interview a group of students standing together in the hallway.
- Interview every tenth student leaving an all-school assembly.
A: Interview every tenth student leaving an all-school assembly.

Q: A worker takes a random sample of 200 bolts and finds that 30 of them are either too long or too short, thus making them unusable. Estimate the number of unusable bolts in a production of 17,000 bolts.
- 1,610 bolts
- 2,550 bolts
- 2,140 bolts
- 2,260 bolts
A: 2,550 bolts

Q: A worker takes a random sample of 200 bolts and finds that 18 of them are either too long or too short, thus making them unusable. Estimate the number of unusable bolts in a production of 7,000 bolts.
- 350 bolts
- 570 bolts
- 420 bolts
- 630 bolts
A: 630 bolts

Q: Out of 1,100 discs tested, 13 are defective. Estimate the number of defective discs in a batch of 41,000.
- about 485 discs
- about 970 discs
- about 4,850 discs
- about 49 discs
A: about 485 discs

Q: Out of 830 discs tested, 32 are defective. Estimate the number of defective discs in a batch of 26,000.
- about 100 discs
- about 2,004 discs
- about 10,020 discs
- about 1,002 discs
A: about 1,002 discs

Q: Out of a random sample of 330 apples, 25 are rated “AAA.” Estimate the number of apples that would be rated “AAA” in a crop of 57,000 apples.
- about 432 apples
- about 4,318 apples
- about 43,180 apples
- about 8,636 apples
A: about 4,318 apples

Q: Out of a random sample of 320 apples, 11 are rated “AAA.” Estimate the number of apples that would be rated “AAA” in a crop of 59,000 apples.
- about 2,028 apples
- about 20,280 apples
- about 4,056 apples
- about 203 apples
A: about 2,028 apples