Chapter 5-3: Binomial Probability Distributions

Assignments and due dates for each chapter are announced in class. Typical problems include:

5-2 page 203

2, 6, 7, 8, 9, 10, 12, 13, 14, 15, 16

Don't compute the mean or standard deviation for problem 10

5-3 page 214

6, 8, 10, 12, 16, 20, 26, 28, 30, 32

Use 95% and Table A-1 or 94% and STATDISK for problem 32)

5-4 page 221

2, 4, 6, 8, 14, 18

5-3 The Binomial Probability Distribution

Binomial Probability Distributions

have a fixed number of trials

each trial is independent of any other trial

each trial results in one of only two outcomes

the probability of the first outcome (usually called 'success') remains fixed throughout all trials

Notation for Binomial Probabilities
Symbol	Item
n	number of trials in the experiment
x	number of successes in n trials
p	probability of success for any 1 trial p = x ÷ n
q	probability of failure for any 1 trial q = 1 – p
P(x)	probability of x successes in n trials

The example on page 210 shows two methods of computing the table of values of x and P(x)

Method 1 (page 210): Use formula 5-5. Unless you are familiar with factorials and exponents, I do not recommend method 1.

Method 2 (page 211): Use Table A-1 on page 609, 610 and 611 to find binomial probability values. Many students find method 2 easier than method 1.

Method 3: Use STATDISK. Click the menu item, Analysis , then highlight and click Binomial Probabilities to open a window in which you enter values for n and p.