Question

the principal of a school plans a school picnic for June 2. a few days before the event, the weather forecast predicts rain for June 2, so the principle decides to cancel the picnic. consider the following information.

in the school's town, the probability that it rains on any day in June is 3%.

when it rains, the forecast correctly predicts rain 90% of the time.

when it does not rain, the forecast incorrectly predicts rain 5% of the time.

let event a be the event that it rains on a day in June. let event b be the event that the forecast predicts rain. do you think the principal...

Answer 1

made a good decision? why or why not?

Answer 2

this is a series of questions

Answer 3

@dan815

Answer 4

what is probability of b given a

Answer 5

P(B l A)

Answer 6

okay what is B and A

Answer 7

in the question

Answer 8

last two lines

Answer 9

P(B|A) means A given B or B given A?

Answer 10

b given a

Answer 11

okay so chance the forecast predicts right given it rains then

Answer 12

when it rains, the forecast correctly predicts rain 90% of the time.

Answer 13

P(B|A)=0.9=90%

Answer 14

a formula for P(B l A) is that is P(A intersection B) times P(A) all divided by P(B)

Answer 15

?

Answer 16

no not times P(A) formula above

Answer 17

how did you figure out that the second thing was that

Answer 18

P(B|A)=P(a n b)/P(b)
like that?

Answer 19

yeah

Answer 20

because the statement is already telling us what we want

Answer 21

no

Answer 22

P(A) at bottom

Answer 23

how did you know it was it

Answer 24

oh sry ya p(a) bottom

Answer 25

P(B|A) is asking the probability of B given A
probability of rain prediction when it rains

Answer 26

and this statement is giving you the answer
"when it rains, the forecast correctly predicts rain 90% of the time. "

Answer 27

oh

Answer 28

now what is P(A)

Answer 29

now what is P(A)

Answer 30

3% chance it rains on a day in june

Answer 31

is a?

Answer 32

ya

Answer 33

\[P \left( a ^{c} \right)\]
is what

Answer 34

.97?