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Archive for November, 2009

15 Google Interview Questions That Will Make You Feel Stupid

Posted by phdblogmeister on November 19, 2009

How many golf balls can fit in a school bus?

Job: Product ManagerAnswer: This is one of those questions Google asks just to see if the applicant can explain the key challenge to solving the problem.

Reader Matt Beuchamp came up with a dandy answer, writing:

I figure a standard school bus is about 8ft wide by 6ft high by 20 feet long – this is just a guess based on the thousands of hours I have been trapped behind school buses while traffic in all directions is stopped.

That means 960 cubic feet and since there are 1728 cubic inches in a cubit foot, that means about 1.6 million cubic inches.

I calculate the volume of a golf ball to be about 2.5 cubic inches (4/3 * pi * .85) as .85 inches is the radius of a golf ball.

Divide that 2.5 cubic inches into 1.6 million and you come up with 660,000 golf balls. However, since there are seats and crap in there taking up space and also since the spherical shape of a golf ball means there will be considerable empty space between them when stacked, I’ll round down to 500,000 golf balls.

Which sounds ludicrous. I would have spitballed no more than 100k. But I stand by my math.

… and 14 others from
http://www.businessinsider.com/answers-to-15-google-interview-questions-that-will-make-you-feel-stupid-2009-11#how-many-golf-balls-can-fit-in-a-school-bus-1

Posted in career | Leave a Comment »

The Null Hypothesis…

Posted by phdblogmeister on November 19, 2009

Carl wants to know whether there is a difference in how fast men drive versus women. He’ll be using radar to clock the speed of every car that goes by for an hour and record whether the driver was a man or woman. In Null Hypothesis testing, the Null Hypothesis must be stated and the study results will lead to either rejecting the Null Hypothesis or not. The Null Hypothesis, symbolized H0, is that there will be no effect. In this case, the Null Hypothesis is that there will be no mean difference between the driving speed of men and the driving speed of women. Just as in America people are considered innocent until proven guilty, we consider that the Null Hypothesis is true unless the data is strong enough to suggest otherwise. After analyzing the data, the Null Hypothesis is either rejected or not. If Carl rejects the Null Hypothesis based on his data, then either men are driving significantly faster than women, or women are driving significantly faster than men.

http://tapuniversity.wordpress.com/2009/11/13/null-hypothesis/

Posted in dissertation | Leave a Comment »

 
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