00:01
Hello.
00:04
So here we have a normal distribution with a mean and standard division.
00:12
A, we want to find a probability that x is less than 40 ,000.
00:26
So for normal distribution, this is the formula.
00:30
And here we're going to have 40 ,000 minus 50 ,000, divided by 20 ,000.
00:49
It's going to be negative 10 ,000 divided by 20 ,000.
00:50
It's going to be negative 10 ,000 divided by 20 ,000.
00:55
0 .5.
00:57
It's a negative value.
01:02
So if we check the z table, we can get this probability.
01:05
That's going to be 0 .3084.
01:15
In percentage, this is going to be 30 .854%.
01:24
We can see this is approximately 31%.
01:31
B, we won the probability between 45 ,000 and 65 ,000.
01:43
65 ,000.
01:53
So we use, we use the same concept.
01:57
So we have 45 ,000 minus 50 ,000 divided by 20 ,000.
02:10
We have our formula in the middle.
02:13
Then here we have 65 ,000 minus 50 ,000 divided by 20 ,000.
02:37
So we have 45 ,000 of 50 ,000...