1) Compute the area under the standard normal curve in the interval [-.75, .75]. What is the 75th percentile of the standard normal curve?
2) There is a data set that closely follows a normal distribution with standard deviation 2 and the percentage of the data exceeding 5 is 0.3. Compute the average value of the data and the percentage of data that are less than 0.
3) Compute the variance of a normal curve if its mean is 5 and the area after 9 under the curve is 0.2