00:01
Hello, let's have a look on the question.
00:03
So for the a part, we have let x be the given random variable.
00:09
So it is given to us that probability of x is equal to 10 is equal to 0 .4 and probability that x is equal to minus 10 is equal to 0 .6.
00:18
So these are the probabilities that are given to us.
00:21
So when we calculate the expectation, so expectation of x will be equal to probability of x equal to 10 multiplied by 10 plus probability of x.
00:31
X is equal to minus 10 multiplied by minus 10.
00:37
So this is equal to 0 .4 multiplied by 10 plus this is 0 .6 multiplied by minus 10.
00:44
This will be equal to 4 minus 6 that is equal to minus 2.
00:48
So from here we can see that expectation of x is equal to minus 2.
00:52
Now we need to calculate expectation of x square.
00:56
So this will be equal to probability that x is equal to 10 multiplied by 10 square plus probability that x is equal to minus 10 multiplied by minus 10 whole square.
01:08
So this is 0 .4 multiplied by 100 plus 0 .6 multiplied by 100...