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# Clarification of confidence interval of difference of means

## Video transcript

near the end of the last video I wasn't as articulate as I would like to be mainly because I think 15 minutes into a video my brain starts to really warm up too much but what I want to do is restate what I was trying to say we got this confidence interval we got a we were confident I'll rewrite it here we're confident that there is a 95% chance or I'll just say that we have a I'll just restate that the confidence interval so there's the 95% confidence interval 90% confidence interval for the mean of this distribution confidence interval interval for the mean of that distribution so the mean of that distribution we got we got as as being one point nine one one point nine one plus or minus one point two one and near the end of the video I tried to explain why that is neat because you know here we have it's you know it's confidence interval for this weird mean of the difference between the sampling meet the mean of the difference between the sampling mean so it's seems kind of confusing but I just want to restate what we saw in previous videos this thing right over here the mean of the difference of the sampling means the mean of the difference of the sampling means we saw two or three videos ago as the same thing as the mean of the of the difference of the means of the sampling distributions so the difference of the means of the sampling distributions and we know that the mean the mean of each of the sampling distributions is actually the same as the mean of the population distributions so this is the same thing as the mean of population of population one minus the mean of population two and this was the neat result about the last video this isn't just a 95% confidence interval for this for this parameter right here it's actually a 95% confidence interval for this parameter right here and this is the parameter that we really care about the true the true difference in weight loss between between going on the diet going on the low-fat diet and not going on the low-fat diet and we have a 95% confidence in that difference is between 0.7 and 3.12 pounds which tells us that we have a 95% confidence interval that you're definitely going to lose some weight we're not a hundred percent sure we have a 95 we know we're 90 we're confident that there's a 95% probability of that anyway hopefully that clarifies it a little bit I didn't want to a confuse you too much with kind of that bungled that bungled language that I had at the last end of the last video