IM 7.8.5 Lesson: More Estimating Probabilities

If the weather forecast calls for a 20% chance of light rain tomorrow, would you say that it is likely to rain tomorrow?

If the probability of a tornado today is [math]\frac{1}{10}[/math], would you say that there will likely be a tornado today?

If the probability of snow this week is 0.85, would you say that it is likely to snow this week?

Work with your group to decide which person will use each spinner. Make sure each person selects a different spinner.

Complete the table below and then answer the first set of questions on your own.

SPINNER A

SPINNER B

SPINNER C

SPINNER D

Spin your spinner 10 times and record your outcomes.

Did you get all of the different possible outcomes in your 10 spins?

What fraction of your 10 spins landed on 3?

Work with your group to answer the next set of questions.

Share your outcomes with your group and record their outcomes.[list=1][*]Outcomes for spinner A:[/*][*]Outcomes for spinner B:[/*][*]Outcomes for spinner C:[/*][*]Outcomes for spinner D:[/*][/list]

Do any of the spinners have the same sample space? If so, do they have the same probabilities for each number to result?

For each spinner, what is the probability that it ends on the number 3? Explain or show your reasoning.

For each spinner, what is the probability that it lands on something other than the number 3? Explain or show your reasoning.

Noah put spinner D on top of his closed binder and spun it 10 times. It never landed on the number 1. How might you explain why this happened?

Han put spinner C on the floor and spun it 10 times. It never landed on the number 3, so he says that the probability of getting a 3 is 0. How might you explain why this happened?

Design a spinner that has a 2/3 probability of landing on the number 3. Precisely draw this spinner.

The applet has a bag of blocks that are different colors. Do not look into the bag or take out more than 1 block at a time. Repeat these steps until everyone in your group has had 4 turns.

[list][*]Take one block out of the bag and record whether or not it is green.[/*][*]Put the block back into the bag, and shake the bag to mix up the blocks.[/*][*]Pass the bag to the next person in the group.[/*][/list][br]What do you think is the probability of taking out a green block from this bag? Explain or show your reasoning.[br]

How could you get a better estimate without opening the bag?