Question

The number of books borrowed weekly from a library follows a normal distribution with a mean of 190 and a standard deviation of 30. Which conclusion does this information best support? There is a 16% chance that more than 250 books are borrowed in a week. There is a 2.1% chance that more than 250 books are borrowed in a week. There is a 68% chance that fewer than 250 books are borrowed in a week. There is an 84% chance that more than 250 books are borrowed in a week. There is an 84% chance that fewer than 250 books are borrowed in a week.

Answer 1

we are given with the mean equal to 190 books, standard deviation of 30 books and is asked in the problem to determine the probability of having more than 250 books borrowed. z score can be computed, that is z = (250-190)/30 = 2. probability using the standard normal distribution table is equal to 0.4772. more than 250 books has a probability of 05-0.4772 equal to 0.0228. answer is b