00:01
For this problem, we're asked to calculate several probabilities using the formula for the probability mass function for the binomial distribution directly, which is to say we're using the probability mass function for the binomial, which is given as follows.
00:30
It's n choose x times p to the exponent x times 1 minus p to the exponent n minus x, and that's if x is equal to 0, 1, 2, up to n, and it equals 0 otherwise.
01:02
Now for a we're given following.
01:15
So using the formula above, we can plug in these values to get.
01:23
So h's 3 times 0 .6 to the exponent 3 times 0 .4 to the exponent 5.
01:39
And this comes out to 56 times 0.
01:43
0 .216 times 0 .010, which equals 0 .124.
01:56
For b, we have the probability mass function for 5 successes out of 8 trials, the probability of success of 0 .6.
02:09
And this equals the following, and that comes out to 0 .279...