00:01
So in this question, we've been given the mean 2 .790.
00:08
Standard deviation to be 4 .58.
00:13
So for part a, a random variable is the monthly income of the resident of daisy city.
00:20
So when we come to the part b, you have to find the probability of x greater than 2250.
00:27
So this will be equal to.
00:31
We know z is given by x minus me over segment.
00:34
So we get 2 -250 minus 2790 over 4 -5 -8 which gives us negative 1 .1790 so our probability of z greater than will be negative 1 .1790 so we can write this as 1 minus probability of 1 .1790 so we can write this as 1 minus probability of 1 z less than we got 1.
01:14
Point negative one point so now i'll write this which is negative i write this as the probability of z less than positive 1 .1790 this actually make more sense so reading this from our standard normal table you're going to get 0 .881 so this is the probability when we come to the secret you have to find the probability of x less than 1985 so our our z will be equal to 1985 minus the mean which is 2790 over 458 which gives us negative 1 .7576.
02:02
So our probability of z less than negative 1 .7576 will be equal to 1 minus.
02:15
So we have one minus the probability of x less than the positive 1 .7576...