6 SV 4) The superintendent of a large school district reads that 60% of middle school students have a personal site on myspace.com. She selects a sample of 50 middle school students at random from her district and has them complete a small survey. One of the questions asks if they have a personal site on myspace.com. Let X denote the number in the sample that say they have such a site. a) What is the mean of X? b) What is the standard deviation of X? c) What is the probability that X is at least 35