Suppose that, after measuring the duration of many telephone calls, a telephone company found their data was well-approximated by the density function p(x)=0.8−0.8x, where x is the duration of a call, in minutes. (a) What percentage of calls last between 1 and 2 minutes? Percent = 100(-e^(-1.6) + e^(-0.8)) percent (b) What percentage of calls last 1 minutes or less? Percent = 100(1-e^(-0.8)) percent (c) What percentage of calls last 4 minutes or more? Percent = 100(e^(-3.2)) percent (d) What is the cumulative distribution function, P()?