Suppose that I randomly ask 148 tourists (n) whether they are from the USA and I got 33 (x) from the USA.

What is the upper level(UL) of the 95% confidence interval that the proportion of all the tourists is from the USA?

I would like to know the average USD amount two people (a couple) spend, the total amount, including Airfares, Hotel, Car Rental, Meals, and all other expenses. So again, I randomly ask n 79 couples of tourists in the Airport:

how much money each couplespent on the whole trip since they, like us, are ready to fly back home.

I then put each individual couple's $ amount into my Excel sheet in one column. I actually calculated the sample mean = 2136 and sample Standard Deviation = 159, assume I want a 95% confidence interval.

Tell me the lower confidence level with 2 decimals (Dollar amount), ex. if the answer is $1256.786, write 1256.79.