Purchase Solution

Confidence Interval: Mean load needed to pull apart pieces of Douglas fir

Not what you're looking for?

Ask Custom Question

How heavy a load (pounds) is needed to pull apart pieces of Douglas fir 4 in long and 1.5 inches square? Here are the data from students doing a laboratory exercise:

33,190 31,300
32,320 26,520
23,040 30,460
24,050 33,650
31,860 28,730
33,020 33,280
30,930 32,700
30,170 32,340
32,590 31,920
32,030
32,720

A) We are willing to regard the wood pieces prepared for the lab session as an SRS of all similar pieces of Douglas fir. Engineers also commonly assume that characteristics of materials vary Normally. Make a graph to show the shape of the distribution for these data. Does the Normality condition appear safe? Suppose that the strength of pieces of wood like these follows a Normal distribution with standard deviation 3000 pounds.

B) Give a 90% confidence Interval for the mean load required to pull the wood apart.

Purchase this Solution

Solution Summary

Confidence intervals for the mean load needed to pull apart pieces are examined.

Solution Preview

The solution file is attached.

How heavy a load (pounds) is needed to pull apart pieces of Douglas fir 4in long and 1.5 inches square?  Here are the data from students doing a laboratory exercise: 

33,190       31,300 
32,320       26,520 
23,040       30,460 
24,050       33,650 
31,860       28,730 
33,020       33,280 
30,930       32,700 
30,170       32,340 
32,590       31,920 
32,030 
32,720 

A)  We are willing to regard the wood pieces prepared for the lab session as an SRS of all similar pieces of Douglas fir.  Engineers ...

Purchase this Solution


Free BrainMass Quizzes
Measures of Central Tendency

This quiz evaluates the students understanding of the measures of central tendency seen in statistics. This quiz is specifically designed to incorporate the measures of central tendency as they relate to psychological research.

Terms and Definitions for Statistics

This quiz covers basic terms and definitions of statistics.

Know Your Statistical Concepts

Each question is a choice-summary multiple choice question that presents you with a statistical concept and then 4 numbered statements. You must decide which (if any) of the numbered statements is/are true as they relate to the statistical concept.

Measures of Central Tendency

Tests knowledge of the three main measures of central tendency, including some simple calculation questions.