Estimating Probability

Open Ended

A carnival game has 160 rubber ducks floating in a pool. The person playing the game takes out one duck and looks at it. If there’s a red mark on the bottom of the duck, the person wins a small prize. If there’s a blue mark on the bottom of the duck, the person wins a large prize. Many ducks do not have a mark. After 50 people have played the game, only 3 of them have won a small prize, and none of them have won a large prize. Estimate the number of the 160 ducks that you think have red marks on the bottom. Explain your reasoning.

Open Ended

A carnival game has 160 rubber ducks floating in a pool. The person playing the game takes out one duck and looks at it. If there’s a red mark on the bottom of the duck, the person wins a small prize. If there’s a blue mark on the bottom of the duck, the person wins a large prize. Many ducks do not have a mark. After 50 people have played the game, only 3 of them have won a small prize, and none of them have won a large prize. Estimate the number of ducks you think have blue marks. Explain your reasoning.

Open Ended

Lin wants to know if flipping a quarter really does have a probability of $$\frac{1}{2}$$ of landing heads up, so she flips a quarter 10 times. It lands heads up 3 times and tails up 7 times. Has she proven that the probability is not $$\frac{1}{2}$$ ? Explain your reasoning.

Open Ended

A spinner has four equal sections, with one letter from the word “MATH” in each section. You spin the spinner 20 times. About how many times do you expect it will land on A? Explain your reasoning.

Open Ended

A spinner has four equal sections, with one letter from the word “MATH” in each section. You spin the spinner 80 times. About how many times do you expect it will land on something other than A? Explain your reasoning.

Multiple Choice

What is the estimated probability of a spin winning this game based on the graph?

• 0.25
• 0.50
• 0.80
• 0.65

Open Ended

There is a bag of 50 marbles. Andre takes out a marble, records its color, and puts it back in. In 4 trials, he gets a green marble 1 time. Estimate the probability of getting a green marble from this bag. Explain your reasoning.

Open Ended

There is a bag of 50 marbles. Jada takes out a marble, records its color, and puts it back in. In 12 trials, she gets a green marble 5 times. Estimate the probability of getting a green marble from this bag. Explain your reasoning.

Open Ended

There is a bag of 50 marbles. Noah takes out a marble, records its color, and puts it back in. In 9 trials, he gets a green marble 3 times. Estimate the probability of getting a green marble from this bag. Explain your reasoning.