Difference between revisions of "SOCR EduMaterials Activities Discrete Distributions"

Revision as of 22:32, 21 October 2006

Description: You can access the applets for the above distributions at http://www.socr.ucla.edu/htmls/SOCR_Distributions.html .

Exercise 1: Use SOCR to graph and print the following distributions and answer the questions below. Also, comment on the shape of each one of these distributions:
- a. \( X \sim b(10,0.5) \), find \( P(X=3) \), \( E(X) \), \( sd(X) \), and verify them with the formulas discussed in class.
- b. \( X \sim b(10,0.1) \), find \( P(1 \le X \le 3) \).
- c. \( \sim b(10,0.9) \), find \( P(5 < X < 8), P(X < 8), P(X \le 7), P(X \ge 9) \).
- d. \( X \sim b(30,0.1) \), find \( P(X > 2) \).

Below you can see a snapshot of the distribution of \( X \sim b(20,0.3) \)

Exercise 2: Use SOCR to graph and print the distribution of a geometric random variable with \( p=0.2, p=0.7 \). What is the shape of these distributions? What happens when \( p \) is large? What happens when \( p \) is small?

Below you can see a snapshot of the distribution of \( X \sim geometric(0.4) \)

Exercise 3: Select the geometric probability distribution with \( p=0.2 \). Use SOCR to compute the following:
- a. \( P(X=5) \)
- b. \( P(X > 3) \)
- c. \( P(X \le 5) \)
- d. \( P(X > 6) \)
- e. \( P(X \ge 8) \)
- f. \( P(4 \le X \le 9) \)
- g. \( P(4 < X < 9) \)

Exercise 4: Verify that your answers in exercise 3agree with the formulas discussed in class, for example, \( P(X=x)=(1-p)^{x-1}p \), \( P(X > k)=(1-p)^k \), etc. Write all your answers in detail using those formulas.

Exercise 5: Let \( X \) follow the hypergeometric probability distribution with \( N=52 \), \( n=10 \), and number of "hot" items 13. Use SOCR to graph and print this distribution.

Below you can see a snapshot of the distribution of \( X \sim hypergeometric(N=100, n=15, r=30) \)

Exercise 6: Refer to exercise 5. Use SOCR to compute \( P(X=5) \) and write down the formula that gives this answer.

Exericise 7: Binomial approximation to hypergeometric: Let \( X \) follow the hypergeometric probability distribution with \( N=1000, n=10 \) and number of "hot" items 50. Graph and print this distribution.

Exercise 8: Refer to exerciise 7. Use SOCR to compute the exact probability\[ P(X=2) \]. Approximate \( P(X=2) \) using the binomial distribution. Is the approximation good? Why?

Exercise 9: Do you think you can approximate well the hypergeometric probability distribution with \( N=50, n=10 \), and number of "hot" items 40 using the binomial probability distribution? Explain.

Translate this page:

(default)	Deutsch	Español	Français	Italiano	Português	日本語	България	الامارات العربية المتحدة	Suomi	इस भाषा में	Norge
한국어	中文	繁体中文	Русский	Nederlands	Ελληνικά	Hrvatska	Česká republika	Danmark	Polska	România	Sverige

@@ Line 45: / Line 45: @@
 * '''Exercise 6:''' Refer to exercise 5.  Use SOCR to compute <math> P(X=5) </math> and write down the formula that gives this answer.
-* '''Exericise 7:''' Binomial approximation to hypergeometric:
+* '''Exericise 7:''' Binomial approximation to hypergeometric:  Let <math> X </math> follow the hypergeometric probability distribution with <math> N=1000, n=10 </math> and number of "hot" items 50.  Graph and print this distribution.
-Let <math> X </math> follow the hypergeometric probability distribution with <math> N=1000, n=10 </math> and number of "hot" items 50.  Graph and print this distribution.
 * '''Exercise 8:''' Refer to exerciise 7.  Use SOCR to compute the exact probability: <math> P(X=2) </math>.  Approximate <math> P(X=2) </math> using the binomial distribution.  Is the approximation good?  Why?