Mindtap Psychology, 2 Terms (12 Months) Printed Access Card For Gravetter/wallnau/forzano’s Essentials Of Statistics For The Behavioral Sciences, 9th
9th Edition
ISBN: 9781337612227
Author: Frederick J Gravetter, Larry B. Wallnau, Lori-Ann B. Forzano
Publisher: Cengage Learning
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Chapter 11, Problem 10P
The stimulant Ritalin has been shown to increase attention span and improve academic performance in children with ADHD (Evans et al., 2001). To demonstrate the effectiveness of the drug, a researcher selects a sample of n – 20 children diagnosed with the disorder and measure each child’s attention span before and after taking the drug. The data show an average increase of attention span of MD = 4.8 minutes with a variance of s2 – 125 for the sample of difference scores.
a. Is this result sufficient to conclude that Ritalin significantly improves attention span? Use a one tailed test with α = .05.
b. Compute the 80% confidence interval for the
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Question 2
A nickel-titanium alloy is used to make components for jet turbine aircraft engines. Cracking is a potentially
serious problem in the final part because it can lead to nonrecoverable failure. A test is run at the parts producer
to determine the effect of four factors on cracks. The four factors are: pouring temperature (A), titanium content
(B), heat treatment method (C), amount of grain refiner used (D). Two replicates of a 24 design are run, and
the length of crack (in mm x10-2) induced in a sample coupon subjected to a standard test is measured. The
data are shown in Table 2.
1
(a) Estimate the factor effects. Which factor effects appear to be large?
(b) Conduct an analysis of variance. Do any of the factors affect cracking? Use a = 0.05.
(c) Write down a regression model that can be used to predict crack length as a function of the significant
main effects and interactions you have identified in part (b).
(d) Analyze the residuals from this experiment.
(e) Is there an…
A 24-1 design has been used to investigate the effect of four factors on the resistivity of a silicon wafer. The data
from this experiment are shown in Table 4.
Table 4: Resistivity Experiment for Exercise 5
Run
A
B
с
D
Resistivity
1
23
2
3
4
5
6
7
8
9
10
11
12
I+I+I+I+Oooo
0
0
||++TI++o000
33.2
4.6
31.2
9.6
40.6
162.4
39.4
158.6
63.4
62.6
58.7
0
0
60.9
3
(a) Estimate the factor effects. Plot the effect estimates on a normal probability scale.
(b) Identify a tentative model for this process. Fit the model and test for curvature.
(c) Plot the residuals from the model in part (b) versus the predicted resistivity. Is there any indication on
this plot of model inadequacy?
(d) Construct a normal probability plot of the residuals. Is there any reason to doubt the validity of the
normality assumption?
Stem1: 1,4
Stem 2: 2,4,8
Stem3: 2,4
Stem4: 0,1,6,8
Stem5: 0,1,2,3,9
Stem 6: 2,2
What’s the Min,Q1, Med,Q3,Max?
Chapter 11 Solutions
Mindtap Psychology, 2 Terms (12 Months) Printed Access Card For Gravetter/wallnau/forzano’s Essentials Of Statistics For The Behavioral Sciences, 9th
Ch. 11.1 - In a repeated-measures study, the same group of...Ch. 11.1 - A researcher conducts a research study comparing...Ch. 11.1 - For an experiment comparing two treatment...Ch. 11.2 - What is the mean for the difference scores for the...Ch. 11.2 - Which of the following is the correct statement of...Ch. 11.2 - Which of the following accurately describes the...Ch. 11.2 - Prob. 4LCCh. 11.3 - A researcher conducts a repeated-measures study...Ch. 11.3 - Prob. 2LCCh. 11.4 - Prob. 1LC
Ch. 11.4 - Prob. 2LCCh. 11.4 - A research report describing the results from a...Ch. 11.4 - Prob. 4LCCh. 11.4 - Prob. 5LCCh. 11.5 - Which of the following possibilities is a concern...Ch. 11.5 - For which of the following situations would an...Ch. 11.5 - Prob. 3LCCh. 11 - For the each of the following studies determine...Ch. 11 - What is the defining characteristic of a...Ch. 11 - A researcher conducts an experiment comparing two...Ch. 11 - A repeated-measures and an independent-measures...Ch. 11 - A sample of n = 16 individuals participates in a...Ch. 11 - Resenhoeft, Villa, and Wiseman (2008) conducted a...Ch. 11 - The following data are from a repeated-measures...Ch. 11 - When you get a surprisingly low price on a product...Ch. 11 - Masculine-themed words (such us competitive,...Ch. 11 - The stimulant Ritalin has been shown to increase...Ch. 11 - College athletes, especially males, are often...Ch. 11 - Callahan (2009) demonstrated that tai chi can...Ch. 11 - Research results indicate that physically...Ch. 11 - There is some evidence suggesting that you are...Ch. 11 - In Example 8.1 (page 200) we discussed a research...Ch. 11 - Solve the following problems. a. A...Ch. 11 - Solve the following problems. a. A...Ch. 11 - A sample of difference stores from a...Ch. 11 - Participants enter a research study with unique...Ch. 11 - Swearing is a common, almost reflexive, response...Ch. 11 - The previous problem demonstrates that removing...Ch. 11 - Explain the difference between a matched-subjects...Ch. 11 - A researcher conducts an experiment comparing two...Ch. 11 - A repeated-measures, a matched-subjects, and an...
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