Shoe manufacturers must know the distribution of foot sizes of different age group. Foot size of 10 inch or above is defined as big size. 23% of 240 randomly selected Ontario men were with big feet. Write down the upper limit of 97% confidence interval for the proportion of Ontario men with big feet. Give your answer to 3 decimal places. (If the CI = (1.2, 3.8) then upper limit of the CI is 3.8)