00:01
Okay, so here we're trying to find like an overall total mean and standard deviation from a couple of independent random variables.
00:10
And because they're independent, we're able to actually solve this.
00:13
So for check -in, we have a 15, let's just write this down, a 15 mean and a standard deviation, one second, a standard deviation of 4.
00:30
Then preop mean 30, standard deviation 6.
00:41
Then medical procedure 25 and 5.
00:48
Recovery 45 and 10.
00:56
Checkout and discharge 20 and 5.
01:01
So here's the interesting thing is that when you have independent random variables, you can add the means together.
01:09
So to get the overall total mean amount of time that would be spent like for the entire procedure, just add them together.
01:16
15 plus 30 plus 25 plus 45 plus 20.
01:21
So we get 135.
01:28
Okay, so to answer the question, assuming that the time in minutes required for each step is an independent random variable, then the mean is going to be 135 minutes.
01:42
Unfortunately, with standard deviation, it doesn't work the same way, but it does work with the variances.
01:47
So we're going to find the variance instead.
01:50
So 4 squared is 16.
01:53
So let me just make a chart here...