calculate the probability

Do your own homework.

Rule:

Do your own homework. CR4 is not a homework cheat site; however, if you have questions about understanding concepts or how a portion of a problem is derived, these types of questions will be accepted.

• What is the probability distribution?
• Will this be continuous time or discrete time distribution?
• Will you be able to defend your answer when the project gets completed at a different time than you predicted?

Do your own homework or at the very least show us some initiative that you understand some of your homework.

In my opinion, if we did not replace after each draw, for example, the answer of ii should be:

P (B) = 4/20=0.25

P(BR)= P(B)x P(R)=(4/20)X(6/20)=0.06

P=P(R|B)= P(RB)/P(B)=0.24

but when considering replacement, it should be:

P=P(BR)= P(B)x P(R)=(4/20)X(6/20)=0.06

You're mixing up your threads here. However, this is a good place to insert some pertinent information.

To calculate the probability that a project task will be accomplished can be reasonably approached using a Weibull distribution. Seeing your other thread on probability, this problem of predicting when a project will be completed and the mathematics of a Weibull distribution is beyond you.

I'm not sure if you are behind in your schooling or reaching farther than you should.

I have realized that whether I do well in exam or not, something certain is that I have gone wrong because I used to study just for study itself, exam and I don't care about whether I can remember it or not at next term. But this is a terrible habit which I have to change now. It's you who make me realize my own problem and remind me of self-examination. Thanks a lot.

This is my thought.

Yeah, I agree with you. I should exchange thoughts instead of using someone else's answer. I will do it time. Thank you for reminding me.

(i) 0

(ii) 0

(iii) 0

Experience has shown that all projects have at least a 20% overrun.

50-50

Depends on whether the environmental impact statements have been approved by the local authorities and the EPA yet. If they are not yet approved, the project probably won't be completed for at least 280 weeks.

Haha, you're quite humorous.

Since your data are normally distributed, convert each number of weeks to a z score and consult your table.

i) P(x≤84): z=(84-80)/8=0.5, Answer = 69.15%

ii) P(x≤92): z=(92-80)/8=1.5, Answer = 93.32%

iii) P(x>90)=P(x≤90): z=(90-80)/8=1.25, Answer = 10.56%