Coal is carried from a mine in West Virginia to a power plant in New York in hopper cars on a long train. The automatic hopper car loader is set to put 66 tons of coal into each car. The actual weights of coal loaded into each car are normally distributed, with mean ? = 66 tons and standard deviation ? = 1.3 ton.   (a) What is the probability that one car chosen at random will have less than 65.5 tons of coal? (Round your answer to four decimal places.) (b) What is the probability that 31 cars chosen at random will have a mean load weight x of less than 65.5 tons of coal? (Round your answer to four decimal places.)

A First Course in Probability (10th Edition)
10th Edition
ISBN:9780134753119
Author:Sheldon Ross
Publisher:Sheldon Ross
Chapter1: Combinatorial Analysis
Section: Chapter Questions
Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...
icon
Related questions
Question

Coal is carried from a mine in West Virginia to a power plant in New York in hopper cars on a long train. The automatic hopper car loader is set to put 66 tons of coal into each car. The actual weights of coal loaded into each car are normally distributed, with mean ? = 66 tons and standard deviation ? = 1.3 ton.

 
(a) What is the probability that one car chosen at random will have less than 65.5 tons of coal? (Round your answer to four decimal places.)


(b) What is the probability that 31 cars chosen at random will have a mean load weight x of less than 65.5 tons of coal? (Round your answer to four decimal places.)


(c) Suppose the weight of coal in one car was less than 65.5 tons. Would that fact make you suspect that the loader had slipped out of adjustment?
Yes or No ? No    

Suppose the weight of coal in 31 cars selected at random had an average x of less than 65.5 tons. Would that fact make you suspect that the loader had slipped out of adjustment? Why?
A.Yes, the probability that this deviation is random is very small.
B. Yes, the probability that this deviation is random is very large.    
C. No, the probability that this deviation is random is very small.
D. No, the probability that this deviation is random is very large.
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 3 steps

Blurred answer
Knowledge Booster
Point Estimation, Limit Theorems, Approximations, and Bounds
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, probability and related others by exploring similar questions and additional content below.
Similar questions
  • SEE MORE QUESTIONS
Recommended textbooks for you
A First Course in Probability (10th Edition)
A First Course in Probability (10th Edition)
Probability
ISBN:
9780134753119
Author:
Sheldon Ross
Publisher:
PEARSON
A First Course in Probability
A First Course in Probability
Probability
ISBN:
9780321794772
Author:
Sheldon Ross
Publisher:
PEARSON