You have a sample mean of 41.5, a population mean of 125 and sample size of 16.find the 95 confidence interval

Answer 1

We are missing needed information: s, the sample standard deviation. We can't compute the confidence interval without that.

Also, we wouldn't typically know the population mean--if we did, there would be no point in estimating it with a sample. In fact, you could argue that any interval containing the value 125 is a 100% confidence interval (since we would know with certainty that such an interval contains the true value), though I highly doubt this was the intent of the question. I suspect an error in transcription (a few, in fact).