Problem 6: (2 pts each) The total nitrogen concentration of the blood plasma of healthy 45 day old albino rats is normally distributed with mean 12.6 g/l (grams/liter) and standard deviation 0.07 g/l.

(a)If a healthy 45 day old albino rat is chosen at random, what* is the probability that the total nitrogen concentration of its blood plasma will be between 12.7 and 13.2 g/l?

(b)Calculate* the value of nitrogen concentration such that 85% of 45 day old albino rats have a nitrogen concentration higher than that value?(Hint: Consider mass under a 'bell curve')

(c)Calculate* the probability that the mean nitrogen concentration level of 9 albino rats randomly chosen from this population will be lower than 12.7 g/l.