Intro Stats
4th Edition
ISBN: 9780321826275
Author: Richard D. De Veaux
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 11, Problem 21E
21–34. What’s the design? Read each brief report of statistical research, and identify
a) whether it was an observational study or an experiment.
If it was an observational study, identify (if possible)
b) whether it was retrospective or prospective.
c) the subjects studied and how they were selected.
d) the parameter of interest.
e) the nature and scope of the conclusion the study can reach.
If it was an experiment, identify (if possible)
b) the subjects studied.
c) the factor(s) in the experiment and the number of levels for each.
d) the number of treatments.
e) the response variable measured.
f) the design (completely randomized, blocked, or matched).
g) whether it was blind (or double-blind).
h) the nature and scope of the conclusion the experiment can reach.
21. Over a 4-month period, among 30 people with bipolar disorder, patients who were given a high dose (10 g/day) of omega-3 fats from fish oil improved more than those given a placebo. (Archives of General Psychiatry 56 [1999]: 407)
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
1. A consumer group claims that the mean annual consumption of cheddar cheese by a person in
the United States is at most 10.3 pounds. A random sample of 100 people in the United States has
a mean annual cheddar cheese consumption of 9.9 pounds. Assume the population standard
deviation is 2.1 pounds. At a = 0.05, can you reject the claim? (Adapted from U.S. Department of
Agriculture)
State the hypotheses:
Calculate the test statistic:
Calculate the P-value:
Conclusion (reject or fail to reject Ho):
2. The CEO of a manufacturing facility claims that the mean workday of the company's assembly
line employees is less than 8.5 hours. A random sample of 25 of the company's assembly line
employees has a mean workday of 8.2 hours. Assume the population standard deviation is 0.5
hour and the population is normally distributed. At a = 0.01, test the CEO's claim.
State the hypotheses:
Calculate the test statistic:
Calculate the P-value:
Conclusion (reject or fail to reject Ho):
Statistics
21.
find the mean.
and
variance of the
following:
Ⓒ x(t) = Ut +V, and V indepriv. s.t
U.VN NL0, 63).
X(t) = t² + Ut +V, U and V incepires have N (0,8)
Ut
①xt = e UNN (0162)
~ X+ = UCOSTE, UNNL0, 62)
SU, Oct
⑤Xt=
7
where U. Vindp.rus
+> ½
have NL, 62).
⑥Xn = ΣY, 41, 42, 43, ... Yn vandom sample
K=1
Text
with mean zen and variance 6
A psychology researcher conducted a Chi-Square Test of Independence to examine whether there is a relationship between college students’ year in school (Freshman, Sophomore, Junior, Senior) and their preferred coping strategy for academic stress (Problem-Focused, Emotion-Focused, Avoidance). The test yielded the following result:
image.png
Interpret the results of this analysis. In your response, clearly explain:
Whether the result is statistically significant and why.
What this means about the relationship between year in school and coping strategy.
What the researcher should conclude based on these findings.
Chapter 11 Solutions
Intro Stats
Ch. 11.3 - At one time, a method called gastric freezing was...Ch. 11.4 - Recall the experiment about gastric freezing, an...Ch. 11 - Steroids The 1990s and early 2000s could be...Ch. 11 - Prob. 2ECh. 11 - Prob. 3ECh. 11 - Tomatoes You want to compare the tastiness and...Ch. 11 - Tips II For the experiment described in Exercise...Ch. 11 - Prob. 6ECh. 11 - Prob. 7ECh. 11 - Prob. 8E
Ch. 11 - Prob. 9ECh. 11 - Prob. 10ECh. 11 - Block that tip The driver of Exercise 3 wants to...Ch. 11 - Blocking tomatoes To obtain enough plants for the...Ch. 11 - Prob. 13ECh. 11 - Prob. 14ECh. 11 - Standardized test scores For his statistics class...Ch. 11 - Heart attacks and height Researchers who examined...Ch. 11 - Prob. 17ECh. 11 - Prob. 18ECh. 11 - Menopause Researchers studied the herb black...Ch. 11 - Honesty Coffee stations in offices often just ask...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - Omega-3 Exercise 21 describes an experiment that...Ch. 11 - Insomnia Exercise 24 describes an experiment...Ch. 11 - Omega-3, revisited Exercises 21 and 35 describe an...Ch. 11 - Insomnia, again Exercises 24 and 36 describe an...Ch. 11 - Omega-3, finis Exercises 21, 35, and 37 describe...Ch. 11 - Insomnia, at last Exercises 24, 36, and 38...Ch. 11 - Injuries Exercise 33 describes an experiment that...Ch. 11 - Tomatoes II Describe a strategy to randomly split...Ch. 11 - Shoes A running-shoe manufacturer wants to test...Ch. 11 - Swimsuits A swimsuit manufacturer wants to test...Ch. 11 - Hamstrings Exercise 33 discussed an experiment to...Ch. 11 - Diet and blood pressure An experiment showed that...Ch. 11 - Mozart Will listening to a Mozart piano sonata...Ch. 11 - Contrast baths Contrast bath treatments use the...Ch. 11 - Prob. 49ECh. 11 - Swimming Recently, a group of adults who swim...Ch. 11 - Dowsing Before drilling for water, many rural...Ch. 11 - Healing A medical researcher suspects that giving...Ch. 11 - Reading Some schools teach reading using phonics...Ch. 11 - Gas mileage Do cars get better gas mileage with...Ch. 11 - Weekend deaths A study published in the New...Ch. 11 - Shingles A research doctor has discovered a new...Ch. 11 - Beetles Hoping to learn how to control crop damage...Ch. 11 - SAT prep Can special study courses actually help...Ch. 11 - Safety switch An industrial machine requires an...Ch. 11 - Washing clothes A consumer group wants to test the...Ch. 11 - Skydiving, anyone? A humor piece published in the...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, statistics and related others by exploring similar questions and additional content below.Similar questions
- A school counselor is conducting a research study to examine whether there is a relationship between the number of times teenagers report vaping per week and their academic performance, measured by GPA. The counselor collects data from a sample of high school students. Write the null and alternative hypotheses for this study. Clearly state your hypotheses in terms of the correlation between vaping frequency and academic performance. EditViewInsertFormatToolsTable 12pt Paragrapharrow_forwardA smallish urn contains 25 small plastic bunnies – 7 of which are pink and 18 of which are white. 10 bunnies are drawn from the urn at random with replacement, and X is the number of pink bunnies that are drawn. (a) P(X = 5) ≈ (b) P(X<6) ≈ The Whoville small urn contains 100 marbles – 60 blue and 40 orange. The Grinch sneaks in one night and grabs a simple random sample (without replacement) of 15 marbles. (a) The probability that the Grinch gets exactly 6 blue marbles is [ Select ] ["≈ 0.054", "≈ 0.043", "≈ 0.061"] . (b) The probability that the Grinch gets at least 7 blue marbles is [ Select ] ["≈ 0.922", "≈ 0.905", "≈ 0.893"] . (c) The probability that the Grinch gets between 8 and 12 blue marbles (inclusive) is [ Select ] ["≈ 0.801", "≈ 0.760", "≈ 0.786"] . The Whoville small urn contains 100 marbles – 60 blue and 40 orange. The Grinch sneaks in one night and grabs a simple random sample (without replacement) of 15 marbles. (a)…arrow_forwardSuppose an experiment was conducted to compare the mileage(km) per litre obtained by competing brands of petrol I,II,III. Three new Mazda, three new Toyota and three new Nissan cars were available for experimentation. During the experiment the cars would operate under same conditions in order to eliminate the effect of external variables on the distance travelled per litre on the assigned brand of petrol. The data is given as below: Brands of Petrol Mazda Toyota Nissan I 10.6 12.0 11.0 II 9.0 15.0 12.0 III 12.0 17.4 13.0 (a) Test at the 5% level of significance whether there are signi cant differences among the brands of fuels and also among the cars. [10] (b) Compute the standard error for comparing any two fuel brands means. Hence compare, at the 5% level of significance, each of fuel brands II, and III with the standard fuel brand I. [10]arrow_forward
- Analyze the residuals of a linear regression model and select the best response. yes, the residual plot does not show a curve no, the residual plot shows a curve yes, the residual plot shows a curve no, the residual plot does not show a curve I answered, "No, the residual plot shows a curve." (and this was incorrect). I am not sure why I keep getting these wrong when the answer seems obvious. Please help me understand what the yes and no references in the answer.arrow_forwarda. Find the value of A.b. Find pX(x) and py(y).c. Find pX|y(x|y) and py|X(y|x)d. Are x and y independent? Why or why not?arrow_forwardAnalyze the residuals of a linear regression model and select the best response.Criteria is simple evaluation of possible indications of an exponential model vs. linear model) no, the residual plot does not show a curve yes, the residual plot does not show a curve yes, the residual plot shows a curve no, the residual plot shows a curve I selected: yes, the residual plot shows a curve and it is INCORRECT. Can u help me understand why?arrow_forward
- You have been hired as an intern to run analyses on the data and report the results back to Sarah; the five questions that Sarah needs you to address are given below. please do it step by step on excel Does there appear to be a positive or negative relationship between price and screen size? Use a scatter plot to examine the relationship. Determine and interpret the correlation coefficient between the two variables. In your interpretation, discuss the direction of the relationship (positive, negative, or zero relationship). Also discuss the strength of the relationship. Estimate the relationship between screen size and price using a simple linear regression model and interpret the estimated coefficients. (In your interpretation, tell the dollar amount by which price will change for each unit of increase in screen size). Include the manufacturer dummy variable (Samsung=1, 0 otherwise) and estimate the relationship between screen size, price and manufacturer dummy as a multiple…arrow_forwardHere is data with as the response variable. x y54.4 19.124.9 99.334.5 9.476.6 0.359.4 4.554.4 0.139.2 56.354 15.773.8 9-156.1 319.2Make a scatter plot of this data. Which point is an outlier? Enter as an ordered pair, e.g., (x,y). (x,y)= Find the regression equation for the data set without the outlier. Enter the equation of the form mx+b rounded to three decimal places. y_wo= Find the regression equation for the data set with the outlier. Enter the equation of the form mx+b rounded to three decimal places. y_w=arrow_forwardYou have been hired as an intern to run analyses on the data and report the results back to Sarah; the five questions that Sarah needs you to address are given below. please do it step by step Does there appear to be a positive or negative relationship between price and screen size? Use a scatter plot to examine the relationship. Determine and interpret the correlation coefficient between the two variables. In your interpretation, discuss the direction of the relationship (positive, negative, or zero relationship). Also discuss the strength of the relationship. Estimate the relationship between screen size and price using a simple linear regression model and interpret the estimated coefficients. (In your interpretation, tell the dollar amount by which price will change for each unit of increase in screen size). Include the manufacturer dummy variable (Samsung=1, 0 otherwise) and estimate the relationship between screen size, price and manufacturer dummy as a multiple linear…arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill
College Algebra (MindTap Course List)AlgebraISBN:9781305652231Author:R. David Gustafson, Jeff HughesPublisher:Cengage Learning
Holt Mcdougal Larson Pre-algebra: Student Edition...AlgebraISBN:9780547587776Author:HOLT MCDOUGALPublisher:HOLT MCDOUGAL
Glencoe Algebra 1, Student Edition, 9780079039897...
Algebra
ISBN:9780079039897
Author:Carter
Publisher:McGraw Hill
College Algebra (MindTap Course List)
Algebra
ISBN:9781305652231
Author:R. David Gustafson, Jeff Hughes
Publisher:Cengage Learning
Holt Mcdougal Larson Pre-algebra: Student Edition...
Algebra
ISBN:9780547587776
Author:HOLT MCDOUGAL
Publisher:HOLT MCDOUGAL
what is Research Design, Research Design Types, and Research Design Methods; Author: Educational Hub;https://www.youtube.com/watch?v=LpmGSioXxdo;License: Standard YouTube License, CC-BY