# Help on stats prob

1. Feb 27, 2005

### mouse

"Within three months, Colgate grabbed the number one market share for toothpaste. Ten months later, 21% of all U.S. households had purchased Total (a product of Colgate) for the first time. During this same period, 43% of those who initially tried Total purchased it again. Colgate Total had been succesfully introduced into the U.S. market."

1) What probabilities are given in this case? Use these probabilities and the probability laws to determine what percentage of U.S. households purchased Total at least twice in the first 10 months of its release.

2) Is age category independent of willingness to try new products? According to the U.S. Census Bureau, approximately 20% of all Americans are in the 45-64 age category. Supposese 24% of the consumers who purchased Total for the first time during the initial 10-month period were in the 45-64 age category. Use this information to determine whether age is independent of the initial purchase of Total during the introductory time period. Explain your answer.

3) Using the probabilities given in Question 1, calculate the probability that a randomly selected U.S. consumer is either in the 45-64 age category or purchased Total during the initial 10-month period. What is the probability that a randomly selected person purchased Total in the first 10 months given that the person is in the 45-64 age category?

Last edited: Feb 27, 2005
2. Mar 1, 2005

3. Mar 1, 2005

### HallsofIvy

Staff Emeritus
1. Why do you want to know? If these are homework problems (and they surely look like it) they should be posted in the homework section. Any you should tell us what you have done on them and what ideas you have regarding them.

2. One of the reasons for doing that is to let us know what definitions and theorems you have to work with. In problem one, I would be inclined to say that, while percentages are mentioned, there are NO probabilities given. But clearly, this problem assumes a wider definition of "probability" than I am using.

4. Mar 1, 2005

### mouse

i was thinking of posting in the homework section but decided to post in here because its the stats section and my question deals with stats.

1. i think its .43 x .32, not sure.

2. i think it deals with some probability, not sure.