In: Statistics and Probability
A bored student starts rolling a die.
(a) Let N7 be the number of tries he needs to get 7 fours. Find a formula for the exact probability P(N7 = 42). You do not have to evaluate it to get a number. To get started note that in order for N7 = 42, the 42nd toss must be a four.
(b) Let N30 be the number of tries he needs to get 30 fours. Use the central limit theorem with the histogram correction to calculate P (N30 ≤ 180).
I Hope you have some idea regarding Random Variables and their Probability Distributions.This Problem is a typical problem which fits in to the setup of Negative Binomial Distribution... See the Images carefully.
In the 6th line the unclear figure is 41.