Answer:
The 99% lower confidence bound for the true average weight loss is 3.98 pounds.
This means that we can be 99% sure that the mean weight loss for all obese adults on a low-carb diet is positive.
Step-by-step explanation:
We have that to find our level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of .
So it is z with a pvalue of , so
Now, find the margin of error M as such
In which is the standard deviation of the population and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 11 - 6.02 = 3.98 pounds
The 99% lower confidence bound for the true average weight loss is 3.98 pounds.
This means that we can be 99% sure that the mean weight loss for all obese adults on a low-carb diet is positive.