Sampling Method

State the type of sample.

In order to determine the average IQ of ninth-grade students, a school psychologist obtains a list of all schools in the local public school system. She randomly selects five of these schools and administers an IQ test to all ninth-grade students at the selected schools.

• Stratified Random Sample

• Cluster Sample

• SRS

• Random Sample

Which of the following doesn’t result in some form of bias?

• Choosing AP students to survey regarding their GPA in order to estimate the average GPA in a school.

• Polling a group of potential voters outside a Republican campaign office in order to estimate the proportion of city residents who favor a particular candidate.

• Surveying people who work in the marketing department of a large corporation in order to assess employee satisfaction with management policies.

• Choosing a stratified random sample of juniors and seniors at a high school in order to estimate the proportion of juniors and seniors who plan to go on to college.

• Asking shoppers leaving a grocery store if they think groceries should cost less in order to estimate the proportion of city residents who think groceries cost too much.

If you choose 5 bingo balls from a basket of 50 balls, what sampling technique are you using?

Which of the following is TRUE?

• In a multi-stage random sample, all individuals and all subsets of the sample size have an equal chance of being selected.

• In a stratified random sample, all individuals and all subsets of the sample size have an equal chance of being selected.

• In a cluster random sample, all individuals and all subsets of the sample size have an equal chance of being selected.

• In a simple random sample, all individuals and all subsets of the sample size have an equal chance of being selected.

An independent research company wants to go door to door to survey people in the city of Fontana. The company decides to number all blocks within the city limit, randomly choose 50 blocks and survey all households on each selected block. 
This is an example of:

• Simple Random Sample

• Stratified Random Sample

• Cluster Random Sample

• Systematic Random Sampling

To randomly select 25 basketball players from the 300 players in the NBA, I would: 

• Number the players from 01-25, read 3 digits at a time from a random table, discarding repeats and numbers over 25, and then stop when I reach 25.

• Number the players from 0-299, read 2 digits at a time from a random table, discarding repeats and numbers over 299, and stop when I reach 25.

• Number the players from 01-299, read 2 digits at a time from a random table, discarding repeats and numbers over 300, and stop when I reach 25.

• Number the players from 001-300, read 3 digits at a time from a random table, discarding repeats, 000 and numbers over 300, and stop when I reach 25.

Farmer Joe's apple tree farm is set up in 100 rows.  He counts the number of apples produced on every 10th row to estimate the number apples produced on the whole farm.  This is _____________ sampling.  

• Random

• Stratified

• Voluntary-Response

• Systematic

A teacher wants to know the average time spent doing homework by the students in her class of 20 girls and 5 boys.
She selects the five closest to her desk.

• simple random

• Voluntary Response

• Convenience

• Systematic Random

Mrs. Croix is conducting a survey to find out the favorite snack of fifth and sixth graders. She will ask a sample of 100 students. Which of the groups below should be surveyed to get the BEST representative sample?

• 100 students at the movie theater

• the first 100 students who go to a local baseball game

• 5 students from each of the 20 local elementary schools

• 20 students from each of the 5 local fifth- and sixth-grade schools

A factory manufactures light bulbs. The factory currently has 300 boxes of light bulbs in its warehouse. To test the quality of bulbs, Alex decides to take out a sample of bulbs and test them to see if they work. Which surveying method will give him the least valid results?

• selecting ten boxes randomly, mixing the bulbs of these boxes together and then selecting ten bulbs randomly

• selecting ten boxes randomly and then selecting one bulb randomly from each box

• selecting one bulb randomly from every tenth box

• selecting one box randomly and then selecting all the bulbs from the box