Lol… I love to scare people. How about opening a box and finding something red in it? Wahahaa…
But then, I think it's more of a surprise? Wahaha…
A black My Melody? Hmm… dip it in black ink? How interesting. Duhz… Use it as appropriate lor. But then, I think My Melody might become something else other than My BLACK Melody if it's used for books: My FLAT Melody… Lol…
Ok, now I know what I need over here at ELove Blogs: The ability to draw simple diagrams here! That will be interesting if it's possible. Hmm.. ok this will be in consideration for my next upgrading.
What a Biased Test.. EE2012.
Read an email. It's just not fair. The instructions are very clear at the top:
Choose 7 out of 9 questions. And now, lecturer “decided to count the best 7 out of 9. So all questions will be graded and the worst two marks will be dropped.”
See the problem here? We are in a statistics course. The probability of passing 7 questions out of 9 is higher than passing 7 questions out of 7. I calculate for you to see.
Let X be the RV for passing 1 particular sub question.
To get more than 80%, we need to get at least 6 full questions correct. If each question has 4 sub questions, we will have to get 24 sub questions correct in order to get at least 80%.
P(Xi) = 1/2.
Let the total number of questions be 7. Therefore, the number of sub questions will be 7 * 4 = 28.
P(X = 24) = 28C24 . (1/2)^28 = 7.63 * 10^-5
Let the total number of questions be 9 now. Therefore, the number of sub questions will now be 9 * 4 = 36.
Since the number of correct questions in order to get 80% is still the same,
P(X = 24) = 36C24 . (1/2)^36 = 1.82 * 10^-2
Hmm…
That's assuming that I attempt the questions by guessing… and that the number of correct answers is fixed. Hmm…
Just feel that, it shouldn't be the way. Why do I feel penalised by that remark? Penalised for following instructions? Penalised for doing ALL 9 questions, and cancelling away 2 of them just because the instruction said “seven”?
Haiz…
Ok… I think I shall carry on, and finish up that question 6… I was doing question 6 when suddenly, engin people came in for their siao siao interviews and I had to get out. After being disturbed, there's no point for me to find another place and sit down and try to finish up the question. So what I did? Go home lor, what else…