00:01
We are told that octopus energy can resolve problems in the same day in 70 % of cases.
00:08
We pick 12 cases at random.
00:11
So the probability that they'll get fixed the same day is 70%, or 0 .7.
00:18
I immediately switch to decimal form because percentages do not play well with our calculations.
00:23
Now, we want to note the number we expect to be resolved and the standard deviation.
00:28
The key here is that this is a binomial.
00:30
Distribution.
00:32
We meet all of the criteria.
00:35
We have a fixed number of trials, n.
00:38
Those trials are independent of each other.
00:41
We just have this sample from the entire selection of cases.
00:44
They should not affect each other.
00:48
There are two outcomes for each, either it is resolved today or it is not.
00:53
And there's a consistent rate at which it will be solved, consistent p...