ALEKS 360 ESSENT. STAT ACCESS CARD
2nd Edition
ISBN: 9781266836428
Author: Navidi
Publisher: MCG
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Textbook Question
Chapter 7.3, Problem 23E
Volunteering: The General Social Survey recently asked 1294 people whether they performed any volunteer work during the past year. A total of 517 people said they did.
a. Find a point estimate for the proportion of people who performed volunteer work during the past year.
b. Construct a 95% confidence interval for the proportion of people who performed volunteer work during the past year.
c. A sociologist states that 50% of Americans perform volunteer work in a given year. Does the confidence interval contradict this statement? Explain.
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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 7 Solutions
ALEKS 360 ESSENT. STAT ACCESS CARD
Ch. 7.1 - Prob. 1CYUCh. 7.1 - Prob. 2CYUCh. 7.1 - Prob. 3CYUCh. 7.1 - Prob. 4CYUCh. 7.1 - Prob. 5CYUCh. 7.1 - Prob. 6CYUCh. 7.1 - Prob. 7CYUCh. 7.1 - Prob. 8CYUCh. 7.1 - Prob. 9CYUCh. 7.1 - 10. Using the output in Exercise 9:
Find the...
Ch. 7.1 - Prob. 11CYUCh. 7.1 - 12. The researchers now plan to construct a 99%...Ch. 7.1 - Prob. 13CYUCh. 7.1 - 14. An IQ test is designed to have scores that...Ch. 7.1 - Prob. 15CYUCh. 7.1 - Prob. 16CYUCh. 7.1 - In Exercises 17–20, fill in each blank with the...Ch. 7.1 - In Exercises 17–20, fill in each blank with the...Ch. 7.1 - Prob. 19ECh. 7.1 - In Exercises 17–20, fill in each blank with the...Ch. 7.1 - In Exercises 21–24, determine whether the...Ch. 7.1 - Prob. 22ECh. 7.1 - Prob. 23ECh. 7.1 - Prob. 24ECh. 7.1 - Prob. 25ECh. 7.1 - In Exercises 25–28, find the critical value zα∕2...Ch. 7.1 - Prob. 27ECh. 7.1 - Prob. 28ECh. 7.1 - Prob. 29ECh. 7.1 - In Exercises 29–32, find the levels of the...Ch. 7.1 - Prob. 31ECh. 7.1 - Prob. 32ECh. 7.1 - Prob. 33ECh. 7.1 - Prob. 34ECh. 7.1 - Prob. 35ECh. 7.1 - 36. A sample of size n = 64 is drawn from a...Ch. 7.1 - 37. A sample of size n = 10 is drawn from a normal...Ch. 7.1 - 38. A sample of size n = 80 is drawn from a normal...Ch. 7.1 - Prob. 39ECh. 7.1 - Prob. 40ECh. 7.1 - Prob. 41ECh. 7.1 - Prob. 42ECh. 7.1 - 43. SAT scores: A college admissions officer takes...Ch. 7.1 - Prob. 44ECh. 7.1 - Prob. 45ECh. 7.1 - Prob. 46ECh. 7.1 - Prob. 47ECh. 7.1 - Prob. 48ECh. 7.1 - Prob. 49ECh. 7.1 - Prob. 50ECh. 7.1 - Prob. 51ECh. 7.1 - Prob. 52ECh. 7.1 - Prob. 53ECh. 7.1 - Prob. 54ECh. 7.1 - Prob. 55ECh. 7.1 - 56. Different standard deviations: Martin and...Ch. 7.1 - Prob. 57ECh. 7.1 - Prob. 58ECh. 7.1 - Prob. 59ECh. 7.1 - Prob. 60ECh. 7.1 - Prob. 61ECh. 7.1 - Prob. 62ECh. 7.1 - Prob. 63ECh. 7.1 - Prob. 64ECh. 7.1 - Interpret computer output: The following MINITAB...Ch. 7.1 - Interpret computer output: The following MINITAB...Ch. 7.1 - Prob. 67ECh. 7.1 - Prob. 68ECh. 7.2 - Prob. 1CYUCh. 7.2 - Prob. 2CYUCh. 7.2 - 3. A potato chip company wants to evaluate the...Ch. 7.2 - Prob. 4CYUCh. 7.2 - Prob. 5CYUCh. 7.2 - Prob. 6CYUCh. 7.2 - Prob. 7ECh. 7.2 - In Exercises 7 and 8, fill in each blank with the...Ch. 7.2 - In Exercises 9 and 10, determine whether the...Ch. 7.2 - In Exercises 9 and 10, determine whether the...Ch. 7.2 - Prob. 11ECh. 7.2 - Prob. 12ECh. 7.2 - Prob. 13ECh. 7.2 - 14. A sample of size n = 22 is drawn from a normal...Ch. 7.2 - 15. A sample of size n = 12 is drawn from a normal...Ch. 7.2 - Prob. 16ECh. 7.2 - 17. A sample of size n = 15 has sample mean and...Ch. 7.2 - Prob. 18ECh. 7.2 - Prob. 19ECh. 7.2 - Prob. 20ECh. 7.2 - Prob. 21ECh. 7.2 - Prob. 22ECh. 7.2 - 23. Fake Twitter followers: Many celebrities and...Ch. 7.2 - Prob. 24ECh. 7.2 - Prob. 25ECh. 7.2 - 26. Sound it out: Phonics is an instructional...Ch. 7.2 - Prob. 27ECh. 7.2 - Prob. 28ECh. 7.2 - Baby weights: Following are weights, in pounds, of...Ch. 7.2 - Eat your cereal: Boxes of cereal are labeled as...Ch. 7.2 - Prob. 31ECh. 7.2 - Mortgage rates: Following are interest rates...Ch. 7.2 - Prob. 33ECh. 7.2 - Big salary for the boss: Following is the total...Ch. 7.2 - Prob. 35ECh. 7.2 - Prob. 36ECh. 7.2 - Prob. 37ECh. 7.2 - Sleeping outlier: A simple random sample of eight...Ch. 7.2 - Prob. 39ECh. 7.2 - Prob. 40ECh. 7.2 - Prob. 41ECh. 7.2 - Prob. 42ECh. 7.2 - Prob. 43ECh. 7.2 - Prob. 44ECh. 7.2 - Prob. 45ECh. 7.2 - Interpret computer output: The following MINITAB...Ch. 7.2 - Prob. 47ECh. 7.3 - A simple random sample of 200 third-graders in a...Ch. 7.3 - Prob. 2CYUCh. 7.3 - A pollster is going to sample a number of voters...Ch. 7.3 - Prob. 4CYUCh. 7.3 - Prob. 5CYUCh. 7.3 - In a simple random sample of 15 seniors from a...Ch. 7.3 - Prob. 7ECh. 7.3 - Prob. 8ECh. 7.3 - Prob. 9ECh. 7.3 - Prob. 10ECh. 7.3 - In Exercises 11–14, find the point estimate, the...Ch. 7.3 - In Exercises 11–14, find the point estimate, the...Ch. 7.3 - Prob. 13ECh. 7.3 - In Exercises 11–14, find the point estimate, the...Ch. 7.3 - In Exercises 15–18, use the given data to...Ch. 7.3 - In Exercises 15–18, use the given data to...Ch. 7.3 - Prob. 17ECh. 7.3 - Prob. 18ECh. 7.3 - Smart phone: Among 238 cell phone owners aged...Ch. 7.3 - Working at home: According to the U.S. Census...Ch. 7.3 - Sleep apnea: Sleep apnea is a disorder in which...Ch. 7.3 - Internet service: An Internet service provider...Ch. 7.3 - Volunteering: The General Social Survey recently...Ch. 7.3 - SAT scores: A college admissions officer sampled...Ch. 7.3 - WOW: In the computer game World of Warcraft, some...Ch. 7.3 - Contaminated water: In a sample of 42 water...Ch. 7.3 - Call me: A sociologist wants to construct a 95%...Ch. 7.3 - Reading proficiency: An educator wants to...Ch. 7.3 - Surgical complications: A medical researcher wants...Ch. 7.3 - Prob. 30ECh. 7.3 - Changing jobs: A sociologist sampled 200 people...Ch. 7.3 - Prob. 32ECh. 7.3 - Small sample: Eighteen concrete blocks were...Ch. 7.3 - Prob. 34ECh. 7.3 - Prob. 35ECh. 7.3 - Prob. 36ECh. 7.3 - Prob. 37ECh. 7.3 - Prob. 38ECh. 7.3 - Prob. 39ECh. 7.3 - Prob. 40ECh. 7.3 - Prob. 41ECh. 7.3 - Prob. 42ECh. 7.3 - Prob. 43ECh. 7.4 - Prob. 1CYUCh. 7.4 - Prob. 2CYUCh. 7.4 - Prob. 3CYUCh. 7.4 - In Exercises 1–4, state which type of parameter is...Ch. 7.4 - Prob. 5ECh. 7.4 - In Exercises 5–10, state which type of parameter...Ch. 7.4 - In Exercises 5–10, state which type of parameter...Ch. 7.4 - Prob. 8ECh. 7.4 - Prob. 9ECh. 7.4 - Prob. 10ECh. 7.4 - Prob. 11ECh. 7.4 - Prob. 12ECh. 7.4 - Prob. 13ECh. 7.4 - Credit card debt: In a survey of 1118 U.S. adults...Ch. 7.4 - Pneumonia: In a simple random sample of 1500...Ch. 7.4 - Prob. 16ECh. 7 - Prob. 1CQCh. 7 - Prob. 2CQCh. 7 - Prob. 3CQCh. 7 - Prob. 4CQCh. 7 - Prob. 5CQCh. 7 - Prob. 6CQCh. 7 - Prob. 7CQCh. 7 - Prob. 8CQCh. 7 - Prob. 9CQCh. 7 - Prob. 10CQCh. 7 - Prob. 11CQCh. 7 - Prob. 12CQCh. 7 - Prob. 13CQCh. 7 - Prob. 14CQCh. 7 - Prob. 15CQCh. 7 - Build more parking? A survey is to be conducted in...Ch. 7 - Drill lifetime: A sample of 50 drills had a mean...Ch. 7 - Cost of environmental restoration: In a survey of...Ch. 7 - More repairs: A sample of six records for repairs...Ch. 7 - Automobile pollution: In a random sample of 85...Ch. 7 - Contaminated water: Polychlorinated biphenyls...Ch. 7 - Defective electronics: A simple random sample of...Ch. 7 - Prob. 8RECh. 7 - High octane: Fifty measurements are taken of the...Ch. 7 - Super Bowl: A simple random sample of 140...Ch. 7 - Prob. 11RECh. 7 - Prob. 12RECh. 7 - Leaking tanks: Leakage from underground fuel tanks...Ch. 7 - Prob. 14RECh. 7 - Prob. 15RECh. 7 - Prob. 1WAICh. 7 - What factors can you think of that may affect the...Ch. 7 - Prob. 3WAICh. 7 - Prob. 4WAICh. 7 - Prob. 5WAICh. 7 - When constructing a confidence interval for μ, how...Ch. 7 - Prob. 1CSCh. 7 - Prob. 2CSCh. 7 - Prob. 3CSCh. 7 - Repeat Exercises 1 and 2 for the Year 2 data. The...Ch. 7 - Prob. 5CS
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