Guessing, if you have no idea which way to guess is more likely, will not have quite the same result as leaving questions blank. Leaving questions blank will add 0 to your score, while guessing will add a mostly-Gaussian random variable with a mean of 0. The math of this is kind of fun:
Guessing, if you have no idea which way to guess is more likely, will not have quite the same result as leaving questions blank. Leaving questions blank will add 0 to your score, while guessing will add a mostly-Gaussian random variable with a mean of 0. The math of this is kind of fun:
http://en.wikipedia.org/wiki/Random_walk
And of course, the central limit theorem is colossally important:
http://en.wikipedia.org/wiki/Central_limit_theorem
No need to invoke that here—directly calculating the probabilities using the binomial distribution is perfectly practical in this instance.