00:01
So our question says a typist makes three error per page on the average.
00:05
What is the probability that it makes number one, no error? question b, five errors on the next page he types.
00:12
So when a random variable or an experiment or a scenario is following is occurring at a fixed rate, then we can use a poisson distribution to represent it.
00:23
Let's read our sentence again.
00:24
A typist makes three errors on the page on the average.
00:28
So meaning on one page, is going to make three error so the event here is actually him making three errors and rate at which the event is occurring is per page so meaning on one page is going to make three errors so if they are going to be five pages there's a number of error that is going to make so events like this scenarios like this where we have an event occurring at a fixed rates in which each of these events are independent on each other we can model events of the stature by using a poisson distribution and we can write it as a random variable egg is dependent is murdered by a poison distribution which is dependent on lambda so lambda is the fixed rates at which the event is occurring so in this case of us our lambda year is actually equals to three so when a random variable follows a poison distribution the probability mass function that defines the probability of successes is given as probability x is equal to x is equals to eris per minus lambda dot lambda raised the above of x divided by x so this is the probability mass function that gives us the probability of success.
01:37
So the first question says what is the probability that is going to make no error.
01:40
By no error we mean, we mean zero error.
01:43
So this simply implies that question a, probability that x is equals to 0.
01:48
So that means erase power minus lambda...