00:01
The mean incubation time of fertilized eggs is 21 days.
00:07
Suppose the incubation times are approximately normally distributed with a standard deviation of one day.
00:16
Determine the 19th percentile for incubation times.
00:22
So the 19th percentile, first we need to find the z value that's closest to 0 .19 in our z table, and i calculated that to be negative 0 .88.
00:37
So to find our number, we're going to take our mu plus our standard deviation times that z value we just found.
00:46
So we get 20 .12, which we could round down to 20 days.
00:56
For part b, find the middle 97 % of days.
01:04
Okay, so the middle 97 % i'm going to draw a really rough sketch of a distribution.
01:11
And if we imagine that this is 97%, and the whole curve is 100%, we have 3 % that we need to split between either end...