3.4 Contingency tables (modified r. bloom)

$\text{P(person is a car phone user) =}$

$\text{P(person had no violation in the last year) =}$

$\text{P(person had no violation in the last year AND was a car phone user) =}$

$\text{P(person is a car phone user OR person had no violation in the last year) =}$

$\text{P(person is a car phone user GIVEN person had a violation in the last year) =}$

$\text{P(person had no violation last year GIVEN person was not a car phone user) =}$

Complete the table.

Are the events "being female" and "preferring the coastline" independent events?

Let $F$ = being female and let $C$ = preferring the coastline.

• A

  $\text{P(F AND C)}$ =

• B

  $\mathrm{P(F)}\cdot \mathrm{P(C)}$ =

Are these two numbers the same? If they are, then $F$ and $C$ are independent. If they are not, then $F$ and $C$ are not independent.

Find the probability that a person is male given that the person prefers hiking near lakes and streams. Let $\text{M}$ = being male and let $\text{L}$ = prefers hiking near lakes and streams.

• A

  What word tells you this is a conditional?

• B

  Fill in the blanks and calculate the probability: $\text{P(\_\_\_|\_\_\_)}=\mathrm{\_\_\_}$ .

• C

  Is the sample space for this problem all 100 hikers? If not, what is it?

Find the probability that a person is female or prefers hiking on mountain peaks. Let $F$ = being female and let $P$ = prefers mountain peaks.

• A

  $\text{P(F)}=$

• B

  $\text{P(P)}=$

• C

  $\text{P(F AND P)}=$

• D

  Therefore, $\text{P(F OR P)}=$