2. We want to compare the average heights of two types of trees. A pilot study shows that the heights of tree type # 1 are between 31 and 50 foot and those of tree type #2 are between 22 and 35 foot. If equal sample sizes are desired, how large should they be in order to ensure that our estimate of the difference in the tree average heights is within 2 foot of the true value with 95% certainty? 3. We want to estimate the difference between the proportion of T/F film fest audience who are MU students and the proportion of T/F film fest audience who are Columbia college students. If we want to be 99% certain that our estimated difference is with .15 of the true difference, how large should the samples be? Assume equal sample sizes.