Hint: You need to first find the z-score and then look the value up in a table of cumulative probabilities. Recall that the z-score of a value is (X - mu)/sigma.
The extract of a plant native to Taiwan has been tested as a possible treatment for Leukemia. One of the chemical compounds produced from the plant was analyzed for a particular collagen. The collagen amount was found to be normally distributed with a mean of and standard deviation of grams per milliliter.
(a) What is the probability that the amount of collagen is greater than grams per milliliter?
(b) What is the probability that the amount of collagen is less than grams per milliliter?
(c) What percentage of compounds formed from the extract of this plant fall within standard deviations of the mean? answer: %