Don't normally ask here for homework help, but I haven't done stats in about 4 years. Knowing that the 5th percentile is 42MPa and the coefficient of variation is 10%, what is the median value?

So far i've found that the z value for this is 0.5199, and by combining COV = SD/Mean and Z = (X - Mean)/SD I found SD = 67.753 (subbing in mean in terms of COV and SD into 2nd eqn). From there the mean = 67.753/0.1 => 677.53MPa. However this value should be around 60MPa. Help :?