Example 2: Representative Sample

If a sample is taken for the purpose of generalizing to a population, the sample must be representative of the population. In other words, it must be similar to the population even though

it is smaller than the population. For example, suppose you are the campaign manager for your friend who is running for senior class president. You would like to know what proportion of

students would vote for her if the election was held today. The class is too big to ask everyone (314 students). What would you do?

Comment on whether or not each of the following sampling procedures should be used. Explain why or why not.

a. Poll everyone in your friend's math class.

b. Assign every student in the senior class a number from 1 to 314. Then, use a random number generator to select 30 students to poll.

c. Ask every student who is going through the lunch line in the cafeteria who they will vote for.

The correct answer is b. Assign every student in the senior class a number from 1 to 314. Then, use a random number generator to select 30 students to poll.

Step-by-step explanation:

You will want that the sample you choose represents the total population, you can do it by random sampling and it requires an unbiased form of collecting data, in which every person has the same opportunity of being chosen.

The correct answer is b. Assign every student in the senior class a number from 1 to 314. Then, use a random number generator to select 30 students to poll, because it uses a random process to select the sample.

a. Poll everyone in your friend's math class, is not the correct answer because the class is too large and it will take a lot of time and effort to ask everyboydy.

c. Ask every student who is going through the lunch line in the cafeteria who they will vote for, is not the correct answer because it is not a random process because the people in the luch line are similar and migth share opinions.