Solution Found!
40 lb/in2The tensile strength of paper is modeled by a
Chapter 4, Problem 193SE(choose chapter or problem)
The tensile strength of paper is modeled by a normal distribution with a mean of 35 pounds per square inch and a standard deviation of 2 pounds per square inch.
(a) What is the probability that the strength of a sample is less than ?
(b) If the specifications require the tensile strength to exceed , what proportion of the samples is scrapped?
Questions & Answers
QUESTION:
The tensile strength of paper is modeled by a normal distribution with a mean of 35 pounds per square inch and a standard deviation of 2 pounds per square inch.
(a) What is the probability that the strength of a sample is less than ?
(b) If the specifications require the tensile strength to exceed , what proportion of the samples is scrapped?
ANSWER:
Step 1 of 4
Given,
The Mean,
The standard deviation,
Suppose that X is a normal random variable with mean and variance . Then,
where Z is a standard normal random variable, and
is the z-value obtained by standardizing X. The probability is obtained by using Appendix Table III.