# MATH: PROBABILITIES

posted by on .

You ask a neighbor to water a sickly plant while you are on vacation. Without water the plant will die with probability 0.85. With water it will die with probability 0.55. You are 89 % certain the neighbor will remember to water the plant.
You come back from the vacation and the plant is dead. What is the probability the neighbor forgot to water it?

• MATH: PROBABILITIES - ,

Well....

I am not %100 percent sure, but I think I have got the right answer.

100-89%=11%

Then, 85% of 11% is 9% (rounded)

So I would say 9%

• MATH: PROBABILITIES - ,

Does this question come form a section in your course called Markov's chains?

if so, then set up a transition matrix with 2 columns called Die, Live and
two rows called water, no water
that would be
.85 .15
.55 .45

multiply that by
.11 .89 -- did water is last number

to get

.58 .417

so there is a 58% chance your neighbour forgot to water.

• MATH: PROBABILITIES - ,

both of you are wrong...

• MATH: PROBABILITIES - ,

any one know the answer:(?

• MATH: PROBABILITIES - ,

You need to use the rule of BAYES and the theorem of total probability.

### Answer This Question

 First Name: School Subject: Answer:

### Related Questions

More Related Questions

Post a New Question