## Comparison of the number of rolls you expected to reach 100 rolls of your selected number, based on the equations and information about probability in the course text, and the number of rolls you actually needed in the experiment you performed.

The theory of probability developed from a study of various games of chance by using coins, dice, and cards. Processes such as flipping a coin, rolling a die, or drawing a card from a deck are called probability experiments. This week we will use classical probability to estimate an outcome, and then test that estimate using empirical probability.

Often when playing gambling games, or collecting items in cereal boxes, one wonders how long it will be before one achieves success. For example, imagine there are six different types of toys with one toy packaged at random in a cereal box. If a person wanted a certain toy, about how many boxes would that person have to buy on average before obtaining that particular toy? Of course, there is the possibility that the particular toy would be in the first box opened or that the person might never obtain the particular toy; although these would be considered rare instances.

To prepare for this Discussion, simulate this same experiment using a single, six-sided die. Choose a particular number—for example, 3. Roll the die until you get your number; that’s one “try.” Make a chart and title it “Tries vs Rolls” Keep rolling until your chosen number is rolled 100 times (100 “tries”), and use your “Tries vs Rolls” chart to Keep track of the number of total rolls needed to roll the number you select 100 times. Ask your friends or family members to help and have fun with you!

1. What did you expect the average to be (from classical probability)?

2. What accounts for the differences from what you expected?

3. Would we get the same thing if we rolled another 100 experiments with the same die?

Post by Day 4 a 200- to 250-word comparison of the number of rolls you expected to reach 100 rolls of your selected number, based on the equations and information about probability in the course text, and the number of rolls you actually needed in the experiment you performed.

Read a selection of your colleagues’ postings.

Respond by Day 7 to two or more of your colleagues’ postings in one or more of the following ways:

• Ask a probing question.
• Share an insight from having read your colleague’s posting.
• Offer and support an opinion.
• Make a suggestion.
• Expand on your colleague’s posting.

Return to this Discussion in a few days to read the responses to your initial posting. Note what you learned and the insights you gained from the comments your colleagues made.

Note: Refer to the Discussion Template in the Course Information area of the course navigation menu for your main post and response.

Resources:

Bluman, A. G. (2014). Elementary statistics: A step-by-step approach (9th ed.). New York, NY: McGraw-Hill.

• Chapter 4, “Probability and Counting Rules” (pp. 185–255)

## Optional Resources

• University of Baltimore. (2015). Dr. Arsham’s statistics site. Retrieved from http://home.ubalt.edu/ntsbarsh/Business-stat/opre504.htm
• Note: Although not required, you may consider reviewing all sections in your course text on Minitab, Microsoft Excel, and TI-83 and 84 as optional material that may be helpful