No wonder I failed…. according to statistics.

note : this is for entertainment purposes only. Nothing to be taken seriously.

I got 4 out of 10 for my STAT101 (Statistics) quiz. So sad. Curious about how I did so badly (like other students in my class), I tried to analyze it.Multiple choice questions are examples of Bernoulli Trial. There are only 2 possible outcomes : right or wrong. According to what I learned in stats, to calculate how big is the probability to get a certain number of successes in a certain number of experiments, we need to use Binomial Distribution.

Confused? Don’t be.

Regarding my MCQ-style test, I had 10 questions on the test. Now, to calculate the probability of having all of the questions answered right, we should use Binomial Distribution.

Binomial Distribution is represented by :

where

(or maybe better known as nCk)

while
n = the number of experiments.
k = the number of successes, can be modified according to our need. (For example if we want to calculate the probability of getting 2 answers right, the k will be 2, and so on)
p = the probability of success in each experiment.

In the case of my MCQ stats quiz which had 10 questions with four choices each, thus :

n = the number of questions, which is 10.
k = 10 (since we want to calculate the probability of getting all the answers right)
p = since there are 4 choices, the probability is 1 out of 4 (1/4)

Okay, now let’s start the calculation..

Let X denote the number of getting the answer of the question right.

Then

Since 10C10 results as 1 and so does 3/4 to the power of 0, what’s left is 1/4 to the power of 10.

And the result is…………………

(use the google calculator, or your own calculator, if you’re too curious)

………………………………. (the tension continues)

9.53674316 × 10^-7 which equals to 9.53674316 × 10^-5 percent.


Ha.

So the probability of having all answers right from 4 choices, ten questions MCQ test is just 9.53674316 × 10^-5 percent.

^{No wonder I failed.}

additional note : the p is only 1/4 when we really really randomly choose. My bad. But FYI, for that stats quiz I really did randomly choose several numbers.

Professor of Spamming

It’s a usual thing for me to get hundreds of spams everyday. But when I checked my Akismet spam box today, there are several spams that caught my eye :

(click to enlarge. Portions blacked out to protect privacy.)

They caught my eye because the URL provided is a .edu URL, which means it’s an address of an educational institution. And well, I checked salisbury.edu to check whether it is a fake, and turned out it’s a real university.

I then checked the more specific URL. The URL leads to a personal page of Salisbury University’s faculty member. Not bad. Professor of Finance. Hm.

I already sent him an e-mail informing this (there is a possibility he’s been infected by a virus/spyware anyway). Wonder what will he reply..

We’ll see.

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The Cheating Vending Machine

SMU is so damn cool that it provides its students with vending machines along with water cooler to ease their thirst!

But it’s not just that. They even managed to put two, not one, vending machines in the concourse, which is undoubtedly a public area.

It even contributes to the public!

My favourite is the vending machine in the concourse below SESS. COz it sells my fave Season Lemon Tea for only 1.30 while 7-11 sells it for 1.70. Can you see the difference?? And you can also pay by ez-link card or cashcard. Well, I never tried it but I think it’s cool for you guys who are too rich to have coins.

Sadly, this vending machine doesn’t like me the way I like it. It likes my money more than it likes me.

The point is, it sometimes received my coins but refused to vend me the drink I want!

How immoral! Money cheater!

But somehow, today, I guess it apologized to me.

I got thirsty after I eat my delicious 3-dollars mee goreng. Off I went to that cheater vending machine bringing 1.50 dollars in coins.

I put my coins in.

I select the drink. Today, it’s not Seasons Lemon Tea but some-brand Orange Pomeade or something. Well it won’t hurt to try something new.

It moved to my selected drink. My selected drink dropped to the belt! But then it stopped…….

………………………………………….

Felt cheated.

But then.

Kaching! Wah! It returned my coins. Yeay babe. Yeay. Complete.
It’s like it’s trying to tell me “Sorry Sylv, I failed. I’m miserable. I don’t deserve your $1.50″.

Then I tried to insert my coins again, and vend the same item.

Oh wow. It moved. The bottle dropped. The belt moved!

Oh yeayyy. I got two bottles now.

Mwahahahahahaha.

Now who’s cheating??

I gave away my second bottle to Wongso, my friend, who happened to meet me.

It’s your lucky day, Wongso.

And if you read this, your pink shirt is just…. appealing. 0,0

Mwahahahahaaha.

Technorati Tags: vending machine, SMU, school, drinks, beverages, cheating, money

Open Source?

Yeay. New category (again??).

Spotted from an article from Kompas which I retrieved from its website.

Bermunculannya situs penyedia layanan blog gratis (open source) semacam Blogspot, youTube, Myspace, Livejournal, serta Friendster kian memanjakan pengguna.

Translation : The appearance of the websites which provide free (open source) blogging service like blogspot, youtube, myspace, livejournal, and friendster makes users more convenient.

Those who know may have known by now.

Okay. Spotted! (it’s like a tagline or something)

free (open source)
gratis (open source)

Hello??? Free isn’t the same with open source! It’s true that open source project is free. But different “free”. As quoted in GNU, it’s free as in free speech, not as in free beer! So, the free blogging platforms mentioned (hey, YouTube isn’t blogging platform is it?), is obviously not open source!

Open source refers to the freedom to access the source code of the program (actually it’s more oftenly used in software). Plus, you can modify it and distribute it, for free.

See the difference? More information can be seen here.

Furthermore, referring a website as an open source website can be
inaccurate. (I’m not really sure about this though. Can someone please
enlighten me?)

OMG. It’s Kompas! The biggest and the most influential newspaper in Indonesia! The paper that my Indonesian Language teacher referred to as the best example of using language rightly and correctly!

Tsk. I wonder what happened in Kompas. Publishing an article like this will surely cause Indonesia-wide misunderstanding. Now blessed be you who read that article and now read my blog post. Be alerted!

Technorati Tags: open source, kompas, indonesia, newspaper, error