# Determining Probability of a Fair Coin Being Flipped 20 Times

A fair coin is flipped 20 times.

3. Determine the probability that the coin comes up tails exactly 15 times.

4. Find the probability that the coin comes up tails at least 15 times. (Include enough details so that It can be understood how you arrived at your answer.)

5. Find the mean and standard deviation for the random variable X in this coin flipping problem.

6. Find the probability that X takes a value within 2 standard deviations of its mean.

https://brainmass.com/statistics/probability/probability-coin-flip-166835

#### Solution Summary

The probability of a coin flip is examined The mean, standard deviation and random variable are determined.

$2.19