00:01
So in this question we're told that we have something which is binomially distributed with n equals 6 and p equals 0 .55.
00:10
So first of all, we want the mean.
00:12
So the mean of x is going to be n p, which is 6 times 0 .55, which is 3 .3.
00:23
Now we need the standard deviation, which is the square root of the variance, and the variance is n p times 1 minus p.
00:32
So we do the square root of 6 times 0 .55 times 0 .45, and that gives us a standard deviation of 1 .22.
00:55
In the exact form, this is 3 root 66 over 20.
01:01
So now see the probability that the number of successes is larger than the mean.
01:07
Well, the mean is 3 .3.
01:09
So the probability that the number of successes is larger than the mean...