Calculating Confidence: Solving a MIT Probability Problem

[birderfox]

Problem:

We have two coins: one is fair and the other coin is a coin that produces heads with probability 3/4. One of the two coins is picked and this coin is tossed n times. Explain how to calculate the number of tosses to make us 95% confident which coin was chosen. You do not have to calculate the minimum value of n, though we would be pleased if you did.

So this problem is a practice problem for a test. I have been trying to solve it for a few hours now and I am kind of stuck. We have been studying random variables, expectation and distributions. Any of you guys have any idea of how to approach this?

Thanks

 

[SW VandeCarr]

Problem:

We have two coins: one is fair and the other coin is a coin that produces heads with probability 3/4. One of the two coins is picked and this coin is tossed n times. Explain how to calculate the number of tosses to make us 95% confident which coin was chosen. You do not have to calculate the minimum value of n, though we would be pleased if you did.

So this problem is a practice problem for a test. I have been trying to solve it for a few hours now and I am kind of stuck. We have been studying random variables, expectation and distributions. Any of you guys have any idea of how to approach this?

Thanks

Use the test for comparing two proportions.