The table shows the result of a restaurant survey.
Meals Service Good Service poor Total
Lunch 49 39 88
Dinner 19 15 34
Total 68 54 122
Find the probability the service was poor, given that the meal was dinner.

I don't know where to begin!

Question

The table shows the result of a restaurant survey.
Meals     Service Good    Service poor    Total
Lunch            49                        39              88
Dinner           19                        15              34
Total              68                        54              122
Find the probability the service was poor, given that the meal was dinner.

I don't know where to begin!

anonymous · Answer

Ok, at dinner, how many people said the service was poor?

anonymous · Answer

15

anonymous · Answer

Out of how many total?

anonymous · Answer

122

anonymous · Answer

Were just looking at dinner, 122 is the total for lunch plus dinner.

anonymous · Answer

ok, then 34

anonymous · Answer

Yep, so the probability is 15/34

anonymous · Answer

Really, that is all that it is asking?

anonymous · Answer

yeah

anonymous · Answer

I wish I was better at this math stuff! thanks!

anonymous · Answer

You're welcome

anonymous · Answer

Let A = the service was poor
Let B = the meal was dinner
we are looking for the conditional probability of A given B, which is
P(A|B)=P(A∩B)P(B)
 What is the probability that the meal was dinner and poor? What is the meal was dinner?

anonymous · Answer

This however is not my answer, I have to give credit to TuringTest honorary professor of mathematics

anonymous · Answer

ask if you have question I finally understand it now ;)