Spinner Probability Investigation (7.SP.1)

Author:: Tom Kroeger, zeimusu, Heather Pierce

Topic:: Bar Chart or Bar Graph, Probability, Random Experiments

We will use a Spinner and Bar Graph to investigate Probability. You spin the spinner by clicking the SPIN button in the corner. The pointer will move counterclockwise. If it lands between two colors, choose the color to the left of the pointer. (For example, if it lands on the line between blue and purple, choose purple)

Click the SPIN! button to spin the spinner.

Record your spins on the Bar Graph by moving the sliders.

Spin the spinner 20 times and record your results in the bar graph.

After 20 spins, how many did you get of each color?

Reset the bar graph, spin another 20 times and record the results.

How many of each color did you get this time? Are they the same amounts for each color as in your first twenty spins? Why do you think so?

Reset the bar graph again and spin another 20 times.

How many of each color did you get for this 3rd time?

Your totals

Add up your total for each color.

Write the Probability

You have just done the probability experiment 60 times. Based on your results, what is your probability for each color? Remember, the probability of a color is the amount of a color you got divided by the total possible outcomes. Here we have 60 total outcomes from the 60 spins. How many did you get for each color? Write your results as P(Red)= P(Orange)= P(Yellow)= P(Green)= P(Blue)= P(Purple)=

Think about it.

If you spun the spinner 100 times, which color or colors do you think is/are most likely to come up? Explain why you think so.

Change the Probability.

Move the points on the edge of the spinner to change the sections of the spinner to whatever sizes you want. Predict which color is most likely to "win" and which color is least likely to come up. Why do you think so?

Check your prediction.

Spin your modified spinner 20 times and record the results. How many of each color did you get? Do they agree with your prediction?