00:01
In this problem, we are given that there is a teacher, and this teacher takes ap statistics test for the class consisting of 60 number of students.
00:13
And it is observed that the average score of all these students, which we will represent with me, this is 2 .8, whereas the standard division of this course, that's 1 .3.
00:24
And we are required to determine the probability that the average score of this class, which we will represent with x bar of course, that's at least three.
00:35
So here we have considered x as the random variable representing this course, and considering this to be normally distributed.
00:43
Let's first use this formula and get the z score corresponding to this sample mean, provided that the sample size, that's 60 of course.
00:51
So now when we put the value of x bar as three, along with the other variables, the value of the c score that we will obtain over here, well, this will be 0 .97 approximately...