1. A headline I USA today describes that "most stay at first job less than two years.' That headline is based upon an Experience.com poll of 320 college graduates. Among those polled, 78% stayed at their first full-time job less than two years.
a) Supposing that 50% is the true percentage of graduates who stay at their first job less than 2 years, find out the mean as well as standard deviation of numbers of such graduates in randomly selected groups of 320 graduates.
b) Assuming that 50 % rate in part (a) is correct, find out the range of usual values for numbers of graduates among 320 who stay at their first job less than two years.
c) Find out the actual number of surveyed graduates who stayed at their first job less than 2 years. Employ the range of values from part
b) to find out whether that number is unusual.
Does the result suggest that the headline isn't justified?
d) This statement was given as part of description of survey technique used: "Alumni who opted-in to receive communications from Experience were invited to participate in online poll, and 320 of them completed the survey." What does that statement propose about the results?