# Difference between revisions of "Eleisha's Segment 32: Contingency Tables: A First Look"

Line 8: | Line 8: | ||

<math>N = 6, p_r = 0.2, p_b = 0.3, \text{and } p_y = 0.5 </math> | <math>N = 6, p_r = 0.2, p_b = 0.3, \text{and } p_y = 0.5 </math> | ||

+ | |||

+ | Want to calculate, P, where P: | ||

+ | |||

+ | <math> P = \text{Prob}(\text{2 red, 2 blue, 2 yellow}| N, p_r, p_b, p_y) </math> | ||

3. A small jelly bean jar has 2 red jelly beans, 3 blue, and 5 yellow. If 6 jelly beans are chosen at random, what is the chance of getting exactly 2 of each color? What is the name of this distribution? | 3. A small jelly bean jar has 2 red jelly beans, 3 blue, and 5 yellow. If 6 jelly beans are chosen at random, what is the chance of getting exactly 2 of each color? What is the name of this distribution? |

## Revision as of 09:50, 10 April 2014

**To Calculate **

1. 20 our of 100 U.S. Senators are women, yet when the Senate formed an intramural baseball team of 9 people only 1 woman was chosen for the team. What is the probability of this occurring by chance? What is the p-value with which the null hypothesis "there is no discrimination against women Senators" can be rejected?

2. A large jelly bean jar has 20% red jelly beans, 30% blue, and 50% yellow. If 6 jelly beans are chosen at random, what is the chance of getting exactly 2 of each color? What is the name of this distribution?

This is a multinomial distribution.

Want to calculate, P, where P:

3. A small jelly bean jar has 2 red jelly beans, 3 blue, and 5 yellow. If 6 jelly beans are chosen at random, what is the chance of getting exactly 2 of each color? What is the name of this distribution?

**To Think About**

1. Suppose that, in the population, 82% of people are right-handed, 18% left handed; 49% are male, 51% female; and that handedness and sex are independent. Repeatedly draw samples of N=15 individuals, form the contingency table, and apply the chi-square test for significance to get a p-value, exactly as described in the lecture segment. How often is your p-value less than 0.05? If you get an answer that is different from 0.05, why? Try larger values of N until the answer converges to 0.05. (How are you handling zero draws when they occur?)

** Back To: ** Eleisha Jackson