Posted by **James** on Saturday, July 27, 2013 at 2:19pm.

2. A statistics professor has asked his students to flip coins over the years. He has kept track of how many flips land heads and how many land tails. Combining the results of his students over many years, he has formed a 95% confidence interval for the long-run population proportion of heads to be (.497, .513).

a. Why is this interval so narrow?

b. Suppose he were to conduct a hypothesis test of whether the long-run population proportion of heads differs from one-half. Based on this interval (do not conduct the test), would he reject the null hypothesis at the .05 significance level? Explain briefly (no more than one sentence).

c. Does the interval provide strong evidence that the long-run population proportion of heads is much different from one-half? Explain briefly.

- Math Statistics -
**PsyDAG**, Sunday, July 28, 2013 at 12:45pm
It seems like you do not have a normal distribution, since the confidence interval goes from .003 below to .013 above .50. The confidence interval is determined by the standard error of the mean (SEm).

SEm = SD/√n

From your data, you would have an extreme large n.

However, without a normal distribution and more data, I cannot answer your last two questions. What was the sample mean? Do you have a typo?

## Answer this Question

## Related Questions

- Math - Four coins fall onto the floor. Find the probability that (a) exactly ...
- maths - Suppose there are 10 coins laid out in front of you. All of the coins ...
- Statistics - suppose you flip a fair coin five times. which of these pairs of ...
- Math - A game is played flipping three coins. If all three coins land heads up ...
- math - francisco tossed the coin 10 more times. he got 5 heads and 5 tails. now ...
- math - you have16 coins that are heads up an18 coins that are tails up. After ...
- Math (please help!) - You have 16 coins that are heads up and 18 coins that are ...
- Math - You have 16 coins that are heads up and 18 coins that are tails up. After...
- Math - You have 16 coins that are heads up and 18 coins that are tails up. After...
- math - Three pennies are tossed into the air.What is the probability they will ...

More Related Questions