00:01
So in this question, they say, suppose that birth weights are normally distributed with a mean of 3 ,466 grams, and a standard deviation of 546 grams.
00:12
Babies above the 95th percentile have a condition called macrosomia, also known as big baby syndrome.
00:21
What birth weight marks the 95th percentile.
00:25
So since i have a normally distributed variable here, we're going to be looking at z scores.
00:31
And so i'm looking at the 95th percentile, i want to look at where 0 .95 lies on the z table.
00:42
So looking at these decimals, i see that 0 .95 occurs around a z score of 1 .64.
00:57
So the 95th percentile corresponds with a z value of about 1 .6 .4.
01:05
So what does that z value of 1 .64 represent? it means i take my mean and i add to this 1 .64 times my standard deviation.
01:20
So my mean this time was 3466...