00:01
So we know that we have two independent binomial situations, and that's going to be part of the requirement.
00:11
And we need to first of all find what the pooled p is.
00:14
And the pooled p, because our first p hat is 45 out of 75, and our second p hat from that second binomial situation is 70 out of 100.
00:28
So the pooled p will end up being 115 out of 175.
00:37
And we could get what the decimal approximation is for that, but i'll just leave it as that.
00:42
And then we want to look at our requirement.
00:44
So we know we have two independent populations.
00:46
And if we take the n1 times the pooled p, the n1 times one minus the pooled p, which is the probability of a failure, and n2 times the pooled p and n sub 2 times 1 minus the pool of p these are all going to be way greater than 5 so we are set to do our analysis by the requirements now part c we want to find out what the difference is between these two and that difference is going to be that 45 over 75 minus the 70 over 100 and when we calculate this is a two proportion z test and so it is a z value and we would take this difference the 45 over 75 minus the 70 over 100 and we'll get that fixed the 70 over 100 now we're assuming that the difference between the two proportions is zero and i forgot to write that down i think that was part part b part c may have been to get what the hypotheses were, that the proportion of one is equal to the proportion of the other, and alternately that the proportions are different.
02:11
So that was probably part c, and then this is probably part d.
02:17
And so now we have the standard deviation on the bottom, and we're going to take that pooled p, which was 115, over 175 times the complement, which is the 60 over 175, divided by the first sample size, which was 75...