Notice that there are currently four color choices. You can see that the theoretical probability of blue is currently 25%. That is because there are four sections of the spinner and blue is one out of four. It is important to remember that in order for the probability to be equally divided among the outcomes, the outcomes must be equally likely. In this case, each section of the spinner must be time same size.
1) What is the theoretical probability of landing on blue if we add another section? How do you know?
2) What is the theoretical probability of landing on blue is we add six sections? How do you know?
3) What happens to the probability of landing on blue as more and more sections are added to the spinner?
To the right of the spinner it says, "Number of Sectors." Push the +1 button four times to add four sections to the spinner. The experimental probability says that there is now a 12.5% chance of landing on each color.
Make a prediction: Do you think that if we spin the spinner eight times, it will land on each color exactly one time? Why or why not?
Now test your prediction. Spin the spinner eight times and see what happens. Record the results from your eight spins into the chart below.
8 spins
Blue Pink Gray
Red
100 spins
1,000 spins
10,000 spins
Answer: Why do you think it didn't land on each color once? It says there is a 12.5% chance of landing on each color, yet, after eight spins we do not have a 12.5% probability of each color.

Make a prediction : How many times do you think you will need to spin the spinner for the relative frequency, or experimental probability, to match the theoretical probability for all eight colors? Do you think it will ever match exactly?
Now we are going to see what happens when we spin the spinner 100, 1,000, and 10,000 times. Don't worry.
You don't actually have to spin the spinner 10,000 times. There is a way for the computer to do it for you. Let's start with 100. Since we have already spun the spinner 8 times, in the box where is says, "Number of Spins" type in 92. Then press spin. This will spin our spinner 92 more times so we have a total of 100. Record your results in the table.
Answer : Did the probabilities for each color get closer to 12.5%? Why do you think this is occurring?
Now we are going to type in 900 so that we can spin the spinner a total of 1,000 times. Record your results in the table.
Answer : Did the probabilities for each color get closer to 12.5%? Why do you think this occurred?
Finally, type in 9,000 so that we can spin the spinner a total of 10,000 times.
Answer : Compare the probabilities from 8 spins to the probability of 10,000 spins. Why do you think the experimental probabilities are so close to the theoretical probabilities now? Compare this to what happened with your penny experiment. Why do you think it took more spins for the relative frequency to reach the experimental probability than it did for penny flips? (Answer in a 5-6 sentence paragraph.)