Sampling in a Fair Way

Warmup

Activity #1

Demonstrate Random Sampling.

• Enter a population size(N)
• Enter Sample size(n).​
• Check the Random Sample box. This generates a random sample.
• Continue to generate more samples with different sizes.

Activity #2

Practice Questions.

• Read the story below and answer the questions that follow.

Lin is running in an election to be president of the seventh grade. She wants to predict her chances of winning. She has the following ideas for surveying a sample of the students who will be voting:

• Ask everyone on her basketball team who they are voting for.​
• Ask every third girl waiting in the lunch line who they are voting for.​
• Ask the first 15 students to arrive at school one morning who they are voting for.

(1.) Would the different methods for selecting a sample lead to different conclusions about the population?

(2.) What are the benefits of each method?

(3.) What might each method overlook?

(4.) Which of the methods listed would be the most likely to produce samples that are representative of the population being studied?

(5). Can you think of a better way to select a sample for this situation?

Challenge #1

Challenge #2

Data collected from a survey of American teenagers aged 13 to 17 was used to estimate that 29% of teens believe in ghosts. This estimate was based on data from 510 American teenagers. What is the population that people carrying out the survey were interested in?

Challenge #3

Jada is using a computer’s random number generator to produce 6 random whole numbers between 1 and 100 so she can use a random sample. The computer produces the numbers: 1, 2, 3, 4, 5, and 6. Should she use these numbers or have the computer generate a new set of random numbers? Explain your reasoning.

Quiz Time

https://www.ixl.com/math/grade-8/identify-representative-random-and-biased-samples