A few days ago

jennifermlayne

Statistics Question?

If one of the pedestrian deaths is randomly selected, find the probability that the driver was intoxicated or the pedestrian was not intoxicated.

I tried to do this using the Formal Addition Rule:

P(A or B) = P(A) + P(B) – P(A or B)

I have these numbers to use:

Drivers Intoxicated: Yes: 59 No: 266

Pedestrian Intoxicated: Yes: 79 No: 581

Here is what I have so far:

P = P(59) + P(79) – P(59 + 79)

If I understand this correctly and have applied it correctly then the answer is 0, this can’t be right.

If this is wrong where did I go wrong? Can you help?

Thanks,

Jennifer

Top 1 Answers

A few days ago

Mitch

Favorite Answer

The Formal Addition Rule should be:

P(A or B) = P(A) + P(B) – P(A *AND* B),

NOT

P(A or B) = P(A) + P(B) – P(A *OR* B)

The probability of a driver being intoxicated:

59/(59 + 266) = 59/325 = 0.1815

The probability of a pedestrian not being intoxicated:

581/(581 + 79) = 581/660 = 0.8803

The probability of a pedestrian not being intoxicated *AND*

the probability of a driver being intoxicated:

(59 + 581)/(59 + 266 + 79 + 581) = 128/197 = 0.6497

0.1815 + 0.8830 – 0.6497 = 0.4148 or 41.48%

For an example on how to do this problem:

http://134.91.165.4/Lehre/Material/Statistik/Triola/sect_03_3.pdf

Good luck in your studies,

~ Mitch ~

What were king james and william penn’s view on religious freedom?

Math homework?? 8th Grade math? Percent increase?

how do convert U.S.dollars in to spain pestas??

Nowadays, who is stronger a man or a woman?

math help!!!?

Need help with a Police Policy topic for class?

Brigham Young University – Algebra 2?