Q3. Dunder Mifflin, a paper company, requires that the paper used for packaging requires a
minimum strength of 20 pounds per square inch. It is known that the strength of this type of
paper follows a normal distribution with a mean of 23 pounds per square inch and a standard
deviation of 2 pounds per square inch. If a paper does not meet the strength requirements, it is
marked as defective.
a) What is the probability of one randomly selected paper to be marked as defective?
b) Suppose a random sample of 100 papers is selected for inspection. What is the
probability that their average strength will be less than 20 pounds per square inch?
c) Suppose a random sample of 100 papers is selected for inspection. What is the
probability that their average strength will be between 20 and 25 pounds per square
inch?
d) What is the minimum paper strength of the top (strongest) 95% of the papers?