There are 30 objective questions in an Economics examination paper.
Let X be the number of questions that I scored correct in the paper.
Therefore X~N(30, 0.25)
0.25 is the probability that I will get a question correct.
0.75 is the probability that I will get a question wrong.
If I magically manage to get every single question correct, the probability for that event occuring will be...
P(X=30) = 30C30 (0.25)30 (0.75)0 = 0.00000000000000000086736
Let's say that I know only half of the paper. So, I estimate that I'll get 15 questions correct...
P(X=15) = 30C15 (0.25)15 (0.75)15 = 0.000000000012445
Then let's say that the gods frown on me, and I shockingly end up with not even a single question correct...
P(X=0) = 30C0 (0.25)0 (0.75)30 = 0.00017858
Hence, the probability of me having no questions correct is definitely higher than me mysteriously scoring all questions correct by random choosing.
I'm so doomed in my Economics.
No. U would be doom not only for economics but for all the other objective papers if u use probability this way...
ReplyDeletegiven that you actually know how to use your statistics, I bet you'd do fine.
ReplyDelete"A bit"?! A BIT?!
ReplyDelete*salutes you* Fellow Math nerd! Hahaha.
Really liked your blog...
ReplyDelete