00:01
So here we have a binomial distribution with total number between 150.
00:05
Probability of success for a single trial is 0 .15.
00:09
We only find the probability that x is over 45, and then we know that this is 0 .081.
00:15
So actually the probability is not very low here.
00:19
So it is possible that she will not have enough price for the event because in total she has 45 prices.
00:28
So when x is over 45, then she does not have enough.
00:33
So the probability is here is 8 .1%.
00:37
So we have 8 .1 % confidence that she will not have enough prices for this event here.
00:48
And then for the normal approximation to the binomial distribution, we know that we just need get the main and variance of the binomial distribution, which can be obtained using the two formulas here.
01:02
So the main of the binomial is np, variance is np times 1 minus p.
01:06
So we can get the main variance for the normal.
01:09
And then again, we need to use the continuous correction here because the normal approximation, the normal distribution is continuous while binomial is discrete.
01:21
So we need to do this correction here...