Assume that the mean hourly cost to operate a commercial airplane follows the normal distribution with a mean of $2,175 per hour and a standard deviation of $245.
What is the operating cost for the lowest 4 percent of the airplanes? (Round z value to 2 decimal places. Omit the "$" sign in your response.)
I assume you can use either a graphing calculator with built-in normal distribution or a normal distribution chart? Either way, check z-value for p<0.04 and get z=-1.75 x=mean+(s.d.)*z=2175-1.75*245=1746.25
