Posted by **John** on Thursday, June 10, 2010 at 6:12pm.

Consider a binomial random variable where the number of trials is 12 and the probability of success on each trial is 0.25. Find the mean and standard deviation of this random variable. I have a mean of 4 and a standard deviation of 2.25 is this correct

- STATISTICS -
**MathGuru**, Thursday, June 10, 2010 at 9:29pm
For this type of problem:

mean = np = (12)(.25) = 3

standard deviation = √npq = √(12)(.25)(.75) = √(2.25) = 1.5

Note: q = 1 - p

- STATISTICS -
**Anonymous**, Friday, November 20, 2015 at 11:31pm
Assume that a procedure yields a binomial distribution with a trial repeated n times. Use the binomial probability formula to find the probability of x successes given the probability p of success on a single trial.

nequals=55, xequals=22, pequals=0.65

## Answer This Question

## Related Questions

- Statistics/probability - The random variable X has a binomial distribution with ...
- Statistics - 1) A Motor Company has purchased steel parts from a supplier for ...
- Math - Expand Your Knowledge: Negative Binomial Distribution Suppose you have ...
- Math - Suppose you have binomial trials for which the probability of success on ...
- math - Suppose x is a random variable with mean and standard deviation. If a ...
- math - let the random variable x denote the number of girls in a five-child ...
- probability - A random experiment of tossing a die twice is performed. Random ...
- Math - Suppose a baseball player had 211 hits in a season. In the given ...
- statistics - In a binomial distribution: A) the random variable X is continuous...
- Elementary statistics - Nine apples, four of which are rotten, are in a ...

More Related Questions