The mean OC for the 31 subjects in question 2 above was 33.4 ng/ml. In our calculations, we assumed that the standard deviation was known to be 19.6 ng/ml.Use the normal approximation to find the approximate bounds on the values of OC that would include these 90, 95, and 99% of the population. If the assumed standard deviation is correct, it would appear that this distribution may be highly skewed. Why?Do you think that this skewness will invalidate the use of the Normal confidence interval in this case?