00:01
Hello.
00:02
So here in this question, are we told the annual rainfall in a certain area is going to be normally distributed with mean 40 and standard deviation 4.
00:09
And we're asked, what is the probability that's starting with the next year? it will take over 10 years before a year with the annual rainfall over 50 is going to occur.
00:20
So here in the given question, we have that new is equal to 40.
00:23
Sigma is 4, x bar is equal to 50, and our sample size is well equal to 10.
00:30
So now we assume that 10 years, the average rainfall is less than 50.
00:35
We have to fund the probability for our less than five years.
00:39
So it's written here, the rainfall is going to be normally distributed.
00:42
So we use the standardized normal table.
00:45
We get that our z value, z, is going to be equal to, well, 50 minus 40...