An article in the ACI Materials Journal (Vol. 84, 1987, pp. 213-216) describes several experiments investigating the rodding of concrete to remove trapped air. A 3-inch x 6-inch cylinder was used, and the number of times this rod was used is the design variable. The resulting compressive strength of the concrete specimen is the response. The data are shown in the following table. Compressive Strength (psi) Observations Rodding Level 10 15 20 25 1530 1530 1440 1610 1650 1500 1560 1730 1530 1500 1490 1510 (a) Is there any difference in compressive strength due to the rodding level? Use a = 0.05. Calculate to 2 decimal places fo Is there statistical evidence to say that rodding level affects compressive strength? (b) Find to 2 decimal places the P-value for the F-statistic computed in part (a). P-value= (c) Analyze the following residual plots to determine model adequacy Does the assumption of normality seem reasonable? Does there appear to be an outlier in the data? Does the assumption of constant variance seem reasonable?

Linear Algebra: A Modern Introduction
4th Edition
ISBN:9781285463247
Author:David Poole
Publisher:David Poole
Chapter7: Distance And Approximation
Section7.3: Least Squares Approximation
Problem 31EQ
icon
Related questions
Question
Normal Score
Reda
Resda
100
100
-100
-100
10
1800
Normal Probability Plot of the Residuals
(response is STRENGTH)
Residual
ResidualsVersus RODDING
poni STRENGTH)
ROODING
ResidualsVersus the Fitted Values
1000
Find Value
100
100
Transcribed Image Text:Normal Score Reda Resda 100 100 -100 -100 10 1800 Normal Probability Plot of the Residuals (response is STRENGTH) Residual ResidualsVersus RODDING poni STRENGTH) ROODING ResidualsVersus the Fitted Values 1000 Find Value 100 100
An article in the ACI Materials Journal (Vol. 84, 1987, pp. 213-216) describes several experiments investigating the rodding of concrete
to remove trapped air. A 3-inch x 6-inch cylinder was used, and the number of times this rod was used is the design variable. The
resulting compressive strength of the concrete specimen is the response. The data are shown in the following table.
Compressive Strength (psi)
Observations
Rodding Level
10
15
20
25
1530 1530 1440
1610 1650 1500
1560 1730 1530
1500 1490 1510
(a) Is there any difference in compressive strength due to the rodding level? Use a = 0.05.
Calculate to 2 decimal places for
Is there statistical evidence to say that rodding level affects compressive strength?
(b) Find to 2 decimal places the P-value for the F-statistic computed in part (a).
P-value=
(c) Analyze the following residual plots to determine model adequacy,
Does the assumption of normality seem reasonable?
Does there appear to be an outlier in the data?
Does the assumption of constant variance seem reasonable?
Transcribed Image Text:An article in the ACI Materials Journal (Vol. 84, 1987, pp. 213-216) describes several experiments investigating the rodding of concrete to remove trapped air. A 3-inch x 6-inch cylinder was used, and the number of times this rod was used is the design variable. The resulting compressive strength of the concrete specimen is the response. The data are shown in the following table. Compressive Strength (psi) Observations Rodding Level 10 15 20 25 1530 1530 1440 1610 1650 1500 1560 1730 1530 1500 1490 1510 (a) Is there any difference in compressive strength due to the rodding level? Use a = 0.05. Calculate to 2 decimal places for Is there statistical evidence to say that rodding level affects compressive strength? (b) Find to 2 decimal places the P-value for the F-statistic computed in part (a). P-value= (c) Analyze the following residual plots to determine model adequacy, Does the assumption of normality seem reasonable? Does there appear to be an outlier in the data? Does the assumption of constant variance seem reasonable?
Expert Solution
steps

Step by step

Solved in 4 steps

Blurred answer
Similar questions
Recommended textbooks for you
Linear Algebra: A Modern Introduction
Linear Algebra: A Modern Introduction
Algebra
ISBN:
9781285463247
Author:
David Poole
Publisher:
Cengage Learning
Glencoe Algebra 1, Student Edition, 9780079039897…
Glencoe Algebra 1, Student Edition, 9780079039897…
Algebra
ISBN:
9780079039897
Author:
Carter
Publisher:
McGraw Hill
Big Ideas Math A Bridge To Success Algebra 1: Stu…
Big Ideas Math A Bridge To Success Algebra 1: Stu…
Algebra
ISBN:
9781680331141
Author:
HOUGHTON MIFFLIN HARCOURT
Publisher:
Houghton Mifflin Harcourt