00:01
In this problem, we are given that there's a normal distribution curve and the 60th percentile, well, that is at the data value 11.
00:11
And along with this, it's also stated that the 25th percentile, that is at 1.
00:18
And we have to find out the mean as well as the standard deviation of the distribution.
00:23
So we will represent the mean with the symbol mu and the standard deviation with the symbol sigma.
00:28
And these are the two things that we have to get.
00:31
So first we use the z table and using that we find that it's the probability that the z score is less than 0 .2533, which is equal to 60 % that 0 .6.
00:43
So this means corresponding to the data value 11, the z score that is equal to 0 .2533.
00:50
So let's use this formula and when we put the values, we will get 0 .2533 equal to 11 minus mean divided by the standard deviation...