00:01
We're being asked to do a margin of error here.
00:04
So i've gone ahead and written out the formula.
00:06
Margin of error, as you guys can see, is equal to 2 times the square root of p, our percent, times the quantity of 1 minus that same p, divided by n, our size of the sample.
00:21
Okay? so it tells me that p is supposed to represent 16%, and n, is 400.
00:35
All we need to do before we start plugging in is fix that percent because we don't plug percentages straight into formulas.
00:42
We have to change them to decimal form first.
00:45
The way you change a percentage to a decimal is you divide that percent by a hundred.
00:51
16 divided by 100 would be 0 .16.
00:55
So we're going to use 0 .16 and 400 and we're just going to plug it straight into the formula.
01:02
So, margin of error, that is a terrible m.
01:09
Good thing i teach math and not english, huh? that is margin of error is equal to 2 times the square root of our p, which is 0 .16, times the quantity of 1 minus that exact same p, 0 .16.
01:32
And then we're going to divide that, make sure that square root extends, then we're going to divide that by our sample size, which in this case we were told is 400.
01:42
Okay, so that is what your setup should look like...