Suppose that the thiocyanate blood concentration in rats fed a normal diet (free of flaxseeds) follows a normal distribution with population mean concentration of 53.3 mg/L and standard deviation of 14.6 mg/L.
(a) How high must a blood thiocyanate concentration be in order to be in the top 15% of the population? Show your work for full credit.
(b) The value you just computed in part (a) is called the _______percentile. (Fill in the blank.)
(c) Would it be unusual to obtain a random sample of seven rats for which their sample mean thiocyanate concentration is more than 70.4 mg/L? Justify your