# Geometric Distribution/Confidence Intervals

• Feb 2nd 2009, 02:16 PM
myeyesfeelmessedup
Geometric Distribution/Confidence Intervals
A die is thrown repeatedly and independently until the score of 6 is obtained. This happens to be on the 8th throw. Find an equi-tailed 95% confidence interval for theta=P(six)?

I understand that the die process follows a geometric distribution. But I can only understand confidence intervals when using a normal distribution? I can calculate the E(X) and Var (X) for the distribution, but i don't see how to calculate the confidence interval? As far as I'm aware the geometric distribution has no fixed "n" and therefore can't calculate the interval in the same way.

Regards
• Feb 3rd 2009, 06:12 AM
mr fantastic
Quote:

Originally Posted by myeyesfeelmessedup
A die is thrown repeatedly and independently until the score of 6 is obtained. This happens to be on the 8th throw. Find an equi-tailed 95% confidence interval for theta=P(six)?

I understand that the die process follows a geometric distribution. But I can only understand confidence intervals when using a normal distribution? I can calculate the E(X) and Var (X) for the distribution, but i don't see how to calculate the confidence interval? As far as I'm aware the geometric distribution has no fixed "n" and therefore can't calculate the interval in the same way.

Regards

JSTOR: Confidence interval

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