Additional Properties of the Binomial Distribution Skill 25
Objectives Compute and for a binomial distribution. Compute the minimum number of trials n needed to achieve a given probability of success P (r).
Mean and Standard Deviation of a Binomial Distribution Two other features that help describe the graph of any distribution are the balance point of the distribution and the spread of the distribution about that balance point. The balance point is the mean of the distribution, and the measure of spread is the standard deviation . The mean is the expected value of the number of successes.
Mean and Standard Deviation of a Binomial Distribution For the binomial distribution, we can use two special formulas to compute the mean and the standard deviation .
Example–Compute and A waiter at the Green Spot Restaurant has learned from long experience that the probability that a lone diner will leave a tip is only 0.7. During one lunch hour, the waiter serves six people who are dining by themselves. Compute the mean and standard deviation.
Example–Compute and n = 6 p = 0.7 q = 0.3 For the binomial distribution, = np = 6(0.7) = 4.2 The balance point of the distribution is at = 4.2
Example–Solution The standard deviation is given by
Example–Riverside Basketball The Riverside basketball team has 75% chance of winning a game. During this coming season Riverside has 9 games before Christmas break. Find the probability of the Riverside basketball team winning exactly 7 games before Christmas breaks.
Example–Riverside Basketball Find n, p, q, and r. Find Probability of the Riverside basketball team winning exactly 7 games before break.
Example–Riverside Basketball Find Probability of the Riverside basketball team winning 7 or more games before break.
Example–Riverside Basketball Find the balance point and standard deviation.
Pick the Right Formula… Discrete Distribution - More than 2 possibilities *Use 5.1 Formulas* Binomial Distribution - 2 possibilities *Use 5.2/5.3 Formulas*
25: Additional Properties of the Binomial Distribution Summarize Notes Homework Worksheet Quiz