00:01
We're told here that 67 % of adults believe that we should continue making pennies, and we have a sample of 15 adults.
00:11
So the number in the sample of 15 who believe that we should continue making pennies follows a binomial distribution, with n equals 15 and probability of success .67.
00:26
Recall that the probability distribution for a binomial is given by this formula, and so to answer the questions.
00:36
For a, we're asked how many of the 15 would we expect to want to keep making pennies? for a binomial, the expected value is sample size times the probability of success.
00:56
So here, that is 15 times .67, and that comes out to 10 .05.
01:12
The standard deviation for a binomial random variable is given by this formula.
01:29
So here we can calculate that as the square root of 15, times .67 times .33.
01:43
And this comes out to 1 .8211.
01:51
So that is part a.
01:52
Expected value is 10 .05...