Bellevue Hospital in New York City uses 100.6 °F as the lowest temperature considered to indicate a fever.
What percentage of normal and healthy adults would be considered to have
Does this percentage suggest that a cutoff of 100.6 °F is appropriate?
There's one critical piece of information missing here, which is a measure of spread (either the standard deviation or the variance) that will tell you the distribution of the temperature of normal and healthy adults. Without that, you can't work out the answer. Do you have that information?
Okay - I've just found it on your other posting. I'll be back when I've done a few calculations.
And actually the calculations you need to perform are pretty much the same as the ones described in parts 1 and 3 of that question, so there's nothing to add here.