00:01
So our question says that assuming a normal can find the lowest score a person could have while being in the following top percentages, emphasis on the world top percentages of a country in mathematics ability.
00:12
So the first question is the top 9%.
00:14
So the first question is the top 9%.
00:18
So that means you are trying to get something of this nature.
00:22
We are trying to have the value of x.
00:26
Let's say this is x that corresponds to the top 9%.
00:29
So this region right here represents the top 9 % and that's a region of 0 .09.
00:34
So let's start with this.
00:36
Once we standardize this, once we standardize this, we have a z score and our diagram is still the same just that we represent the x right now which is z.
00:54
So we have something of this nature.
00:56
We have here z and this is the region i'm interested in.
01:00
So we have here at 0 .09 and this is going to be 0 .91, this region right here.
01:06
So we can actually work or get the value of z corresponding to the top 9 % either using this area to the right or this area to the left.
01:15
So the table i will be using, this is my table right here.
01:19
If you take a look at the instruction on my table, it says the table entry for z is the area under the standard normal to the left of z...