Point the number of accidents that occur at busy...

The number of accidents that occur at busy intersection is Poisson distributed with mean of 3.6 per week: Find the probability of the following events. No accidents occur in one week: Probability 6 or more accidents occur in week: Probability C. One accident occurs today: Probability

Transcript

00:01 Hello, so we have a purson distribution with a mean of 3 .6 per week.

00:08 So lambda is 3 .6 per week.

00:19 Before, let's look at the formula for purson distribution.

00:25 It's e to the negative lambda times lambda to the x over x factorial.

00:35 Okay, now a, we want to find the probability there are no accidents, okay, in one.

00:41 Week so we are finding probability of x equals 0 is going to be e to the negative 0 .6 times 30 .6 is putting 0 over 0 factorial so this is just e to the negative 3 .6 e to the negative 3 .6 e to the negative 3 .6 to 4 decimal places we're going to have 0 .073 the next one is the probability that six or more accidents as probability of x greater than or equal to 6.

01:41 This is the same as 1 minus the probability of x less than or equal to 5.

01:50 So let's look at what this means.

01:55 What this means is that we have to do probability from x to 0 all the way up to probability that x equals 5.

02:12 So we can see that this is going to be a lot of work.

02:14 So the alternative is to use excel.

02:18 So let's look at using excel.

02:24 So we are using excel for the one in bracket.

02:27 So for excel, we're just going to type in equal to puisson.

02:37 Our first entry is going to be 5.

02:41 The next one is our mean value, 3 .6.

02:44 And we're going to type here true.

02:49 So we type in true because we want the probability from 0 to 5.