Question 2: The confidence intervals are all calculated using the Normal distribution and standard error method. Why should these confidence intervals be treated with great caution?
Normal distribution and standard error methods are large sample methods, relying on the fact that statistics calcuated from large samples follow a Normal distribution and have a reliable standard error estimated from the data.
Here one of our two groups, diabetics, is quite small, only 10 subjects, so these methods may not be very reliable.
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