# SOCR Courses 2009 2010 Stat13 1 Lab3

## Stats 13.1 - Laboratory Activity 3

You can access the applet for any of the SOCR distributions at http://www.socr.ucla.edu/htmls/SOCR_Distributions.html. Use SOCR to graph the following distributions and answer the questions below. Also, comment on the shape of each one of these distributions.

### Binomial Distribution Activity

#### Problem 1

• X~Binom(10,.5)
• Find: P(x = 3),E(X), sd(X) and verify them with the formulas discussed in class.

#### Problem 2

• X~Binom(10,.1)
• Find and verify:
• P(1 <= x <= 3)

#### Problem 3

• X~Binom(10,.9)
• Find and verify:
• P(5 < x < 8)
• P(x < 8)
• P(x <= 7)
• P(x >= 9)

#### Problem 4

• X~Binom(30,.1)
• Find and verify: P(x > 2)

### Distribution Comparison

• Graph and comment on the shape of the binomial distribution with n = 20, p = 0.1 and then with n = 20,p = 0.9 (take a snapshot of each).
• Now, keep n = 20 but change p = 0.45. How about when n = 80,p = 0.1? Take another snapshot.
• What changes do you observe in the distribution as the parameters change? Watch both the change in shape as well as the changing number on the x and y axes.

 Smaller n Larger n Smaller p Larger p