00:02
What sample size do we need to get a margin of error no greater than 3 % at 95 % confidence? so our margin of error formula looks like this, where m -o -e is margin of error.
00:14
So we want that to be 3 % or .03 is a decimal.
00:18
At 95 % confidence, z is 1 .96.
00:23
And then underneath our square root here, we're going to do our proportion of employees that are satisfied is 0 .7, 70%.
00:32
1 minus 0 .70.
00:35
And then n is our sample size that we don't know.
00:39
So we're going to need to use some algebra to solve this for n.
00:42
So the first thing we're going to do is divide both sides of this equation by 1 .96.
00:48
And on the left, that's going to make a small decimal of 0 .015306, 1224 equals that square root.
01:04
And now up in the numerator there, let's multiply 0 .7 times 1 minus 0 .7...