So for this question we will be using the formula for all three parts is c squared standard deviation squared quite a by the evil he squared. So for a we have a standard deviation of four, We have a 95 confidence interval. Mhm And E equals one. So first made after you switch the confidence interval into a Z score, So you would change it to a distance of traffic from one And then take that divided by two. And for this one you get .025, you look that up on what that score would be on AC table Andrew Value is 1.96. So that's what you'll be using the formula. There we go. 1.96 squared times four square divided by one square, which would just be one of course. And when you put this in the calculator, you get 61.5, but you would need to round up Because you can't really have a half a person, so it would be 62, the property well, I do something pretty much just saying, be just different value. So you have the standard deviation up for 90 99% confidence interval, Your E is equal to one. So switch the comments and a rule to a Z score again. Oh right, to and you get points here is your efi and when you look that up on easy table, The value is 2.58, So now we can plug that into the formula To be 2.58 squared Times four square divided by one squared again, This one you hit when I was 6.5, but we would need to round up For this case, so the minimum participants would be 107. And then finally, for C you have a standard deviation for 895% confidence interval, what he is able to 8950.5 and because we already did the confidence interval to disease from apartment, we can just use that number. I was walking Point or 1.96, I was four squared divided by a half squared and you get 235.9. But again, we have to round up, so that would be A minimum of 246 participants. Okay?