00:01
All right, so we have ambulance response time measured in minutes between the interval, the call to the ems and when the patient is reached.
00:10
And for a particular station, we'll call station a, the response time is known to be seven and a half minutes with a mean of two, a standard deviation of two and a half, and it is normally distributed.
00:20
So since it's normally distributed, we can use a z score to find some probabilities here.
00:25
And regulations require that 90 % of all emergency calls should be released, reach within nine minutes or less.
00:31
So what we're actually looking here is to find the probability that this station gets to the call with a less than nine minutes with a 90 % chance of probability.
00:42
So what we're going to do is convert this to a z score.
00:44
So it's going to be nine minus, oops, i forgot the z.
00:48
So this is the same as probably z is less than nine minus 7 .5 over 2 .5.
00:55
That's going to be 1 .5 divided by 2 .5 or 0 .6.
01:00
So this is the probability, z is less than 0 .6, which is 0 .727, so approximately 72 .5%.
01:19
So since only 72 .5 % of calls are reached within nine minutes, station a is not meeting the regulations...