MATH312—Jayme Rosenquist
Chapter 29—Introduction to Statistics and Sampling 10/09/18
29.3 – Simulating Random Sampling
A class wants to go to Disneyland. They decide they want to sell raffle tickets for a Wii, but they
want to know how many people would be interested in buying raffle tickets. In this school there
are grades 1-6 with 100 kids in each grade.
Doug wants the same number of boys and girls from each grade so he randomly selected 5 boys
and 5 girls from each grade, 30% said they would be interested.
- This is okay, but not great. This is a stratified example. It does not guarantee that every
class has 50 girls and 50 boys. Thus, the probability of a girl being selected could be
higher compared to that of a boy.
Options for polling 10 kids from one grade:
• Number each student {1, 2 … 100} and randomly select 10 random numbers from a hat.
• If using a table of random numbers, we can assign each student a number.
How can we estimate the proportion or red and green balls in a container, if the container
contains 1,000 balls of unknown proportions?
- One option would be if we pulled a random sample of sufficient size and recorded the
properties of red and green balls. These would be our sample statistics. We use these to
approximate the population parameters.