00:01
Hey there, welcome to numerate.
00:03
So we are looking at a person named john, the length of time and minutes that he drives to work each morning.
00:12
So we're given an average and standard deviation of the population.
00:16
So for randomly selected morning, what is the probability that he drives between 36 and 40 minutes? so let's write down our mean and standard deviation values first.
00:30
We're given a mean of 38 minutes.
00:32
Minutes and a standard deviation value of five.
00:39
So the probability that we're working with here is x is between 36 and 40 minutes.
00:58
So we set up a z -score equation over here.
01:01
We have, well, before we set up z -score, we had to split this probability into two parts.
01:09
So let's do that.
01:11
X is less than 40 equals.
01:16
And the probability, the x is less than 36.
01:23
So now we can find a z score for each of these probabilities.
01:27
We take out 40 amount, subtract it to our mean, and divided by our standard deviation of 5.
01:39
This will give us a z score.
01:43
That equals around 0 .4...