DS280 - Intro to Statistics

Lecture Review #4 - Conditional Probability

OBJECTIVES:

After today's class you should:

• understand statistical concepts and terminology used to describe the relationships between events (independent, dependent, mutually exclusive).
• understand the concept of conditional probability.
• know how to set up, interpret, and use contingency tables.
• be familiar with Simpson's paradox.

REVIEW QUESTIONS:

1) What are "independent" events? "Dependent" events? "Mutually exclusive" events. Give examples to illustrate.

2) What is meant by a "conditional" probability?

3) What is Simpson's paradox?

COMPUTATIONAL EXERCISES:

1) Circulation data indicate that 40% of the population of DeLand read the Daytona Beach News-Journal, while 15% read the DeLand Beacon - with 10% of the city reading both papers. What fraction of News-Journal readers also read the Beacon?

2) You are dealt a poker hand of five cards from a standard 52-card deck. What is the probability you are dealt a "flush" (that is, all five cards from the same suit)?

3) Create a data set of your own that illustrates Simpson's paradox.

SOLUTIONS:
1) .25
2) .00198
SEE DETAILED SOLUTIONS