SigalCohen
New member
- Joined
- Dec 3, 2021
- Messages
- 2
A pack has 4 original candles and 12 alternative. Their burning time is normally distributed with average and standard deviation:
Original: X~N(4, 0.5).
Alternative: Y~N(3, 0.25).
Therefor:
P(X)=4/16=0.25
P(Y)=12/16=0.75
The questions are:
A. A randomly selected candle is lit for at least 3hr. What is the probability that it is original?
B. Given that 2 out of 3 candles randomly selected from pack A are alternatives. What is the probability that at least 2 out of 5 candles chosen at random from pack B will be original?
First, I need to find the probability of getting a candle lit for at least 3 hours:
P(candle>=3) = P(X>=3)*P(X) + P(Y>=3)*P(Y)
Then I can find the conditional probability:
P(X|candle>=3) = (P(X>=3)*P(X))/P(candle>=3) = 0.244/0.6175 = 0.39
As far as this section am I right??
Thank you all!
Original: X~N(4, 0.5).
Alternative: Y~N(3, 0.25).
Therefor:
P(X)=4/16=0.25
P(Y)=12/16=0.75
The questions are:
A. A randomly selected candle is lit for at least 3hr. What is the probability that it is original?
B. Given that 2 out of 3 candles randomly selected from pack A are alternatives. What is the probability that at least 2 out of 5 candles chosen at random from pack B will be original?
First, I need to find the probability of getting a candle lit for at least 3 hours:
P(candle>=3) = P(X>=3)*P(X) + P(Y>=3)*P(Y)
Then I can find the conditional probability:
P(X|candle>=3) = (P(X>=3)*P(X))/P(candle>=3) = 0.244/0.6175 = 0.39
As far as this section am I right??
Thank you all!