00:01
For this problem, we are told that a random sample of 10 chocolate energy bars, so n equals 10, of a certain brand has, on average, 230 calories per bar, so x bar equals 230.
00:12
With a standard deviation, sigma, of 15 calories.
00:16
We are asked to construct a 99 % confidence interval, so we have alpha equals 0 .01, for the true mean calorie content of this brand of energy bar.
00:26
Assume that, or we are told, to assume that the district, of the calorie content is approximately normal.
00:33
So what we can do here is recognize that the confidence interval is going to be equal to x bar plus or minus z of alpha over 2, so 0 .005, times sigma divided by the square root of n...