1. Survey 30 people to find out if they are left-handed or right-handed, and use the following chart to assemble a contingency table with the information.

Left handed Right handed Total Female Male Total

2. Answer the following questions about the information in your contingency table:

• If a person is randomly selected from the survey participants, what is the probability that the person will be left-handed?
• If you randomly choose a female from the people you surveyed, what is the probability that she is left-handed?
• What is the odds ratio of choosing a left-handed female?
• What is the relative risk of choosing a left-handed female?

Example

Example Green Blue Total Cats 40 (A) 20 (B) 60 (A+B) Dogs 30 (C) 40 (D) 70 (C+D) Total 70 (A+C) 60 (B+D) 130 (A+B+C+D) a. Probability of Green - (A+C)/(A+B+C+D): 70/130 = 0.54 b. Probability of Green Cat - A/(A+B): 40/60 = 0.67 c. Odds Ratio of Green Cat - (A/B)/(C/D) or AD/BC: (4040)/(2030) = 1600/600 = 2.67 op d. Relative Risk of Green Cat - [A/(A+C)]/[B/(B+D)]: (40/70)/(20/60) = 1.71