OPENINTRO:STATISTICS
4th Edition
ISBN: 9781943450077
Author: OPENINTRO
Publisher: amazon.com
expand_more
expand_more
format_list_bulleted
Videos
Question
Chapter 1.4, Problem 30E
a.
To determine
Identify the type of study and give reason.
b.
To determine
Identify the explanatory variables and response variables.
c.
To determine
Identify whether the patients are blinded.
d.
To determine
Identify whether the study is double-blind.
e.
To determine
Identify whether a confounding variable is introduced in the study.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
A health psychologist was interested in the effects of vitamin supplements on the
immune system. Three groups of adults were exposed (in a highly ethical way) to the
cold virus; one group took no supplements for a week before exposure, another had
vitamin C supplements, and a third had multivitamins (excluding C). The severity of
the cold was measured as a percentage (0% = not contracted, 100% = very severe
symptoms). The psychologist also measured the number of cigarettes that each
person smoked per day, as smoking suppresses the immune system. The
psychologist was interested in the differėnces in the severity of the illnesses across
different vitamin groups accounting for cigarette usage. What technique should be
used to analyse these data?
An experimenter wants to study the relationship between type of milk and infant growth in underdeveloped countries. She randomly assigns 300 infants to either a breast-feeding group or an infant formula group. She then weighs the infants every three days for the first four weeks of life.
A study was developed to evaluate effectiveness of a weight loss diet plan. An ad was placed in two towns to locate study participants who were to follow the diet. In Town A, the clinicians asked each dieter to report how much weight they had lost over the previous 6 weeks while following the diet. In Town B, the clinicians weighed each dieter at the beginning of the study and again after 6 weeks on the diet program. The weight lost was calculated as the difference between the beginning weight and the weight after 6 weeks. At the end of the study, it was determined that Town B had lost significantly less weight than Town A.
1.What is the population of interest in this situation?
2. Identify source(s) of bias in this study.
Chapter 1 Solutions
OPENINTRO:STATISTICS
Ch. 1.1 - Prob. 1GPCh. 1.1 - Prob. 1ECh. 1.1 - Prob. 2ECh. 1.2 - Prob. 2GPCh. 1.2 - Prob. 3GPCh. 1.2 - Prob. 4GPCh. 1.2 - Prob. 6GPCh. 1.2 - Prob. 7GPCh. 1.2 - Prob. 3ECh. 1.2 - Prob. 4E
Ch. 1.2 - Prob. 5ECh. 1.2 - Prob. 6ECh. 1.2 - Prob. 7ECh. 1.2 - Prob. 8ECh. 1.2 - Prob. 9ECh. 1.2 - Prob. 10ECh. 1.2 - Prob. 11ECh. 1.2 - Prob. 12ECh. 1.3 - Prob. 9GPCh. 1.3 - Prob. 11GPCh. 1.3 - Prob. 12GPCh. 1.3 - Prob. 13GPCh. 1.3 - Prob. 13ECh. 1.3 - Prob. 14ECh. 1.3 - Prob. 15ECh. 1.3 - Prob. 16ECh. 1.3 - Prob. 17ECh. 1.3 - Prob. 18ECh. 1.3 - Prob. 19ECh. 1.3 - Prob. 20ECh. 1.3 - Prob. 21ECh. 1.3 - Prob. 22ECh. 1.3 - Prob. 23ECh. 1.3 - Prob. 24ECh. 1.3 - Prob. 25ECh. 1.3 - Prob. 26ECh. 1.3 - Prob. 27ECh. 1.3 - Prob. 28ECh. 1.4 - Prob. 16GPCh. 1.4 - Prob. 17GPCh. 1.4 - Prob. 29ECh. 1.4 - Prob. 30ECh. 1.4 - Prob. 31ECh. 1.4 - Prob. 32ECh. 1.4 - Prob. 33ECh. 1.4 - Prob. 34ECh. 1 - Prob. 35ECh. 1 - Prob. 36ECh. 1 - Prob. 37ECh. 1 - Prob. 38ECh. 1 - Prob. 39CECh. 1 - Prob. 40CECh. 1 - Prob. 41CECh. 1 - Prob. 42CECh. 1 - Prob. 43CECh. 1 - Prob. 44CE
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
- I need help with this problem.arrow_forwardA pharmaceutical company conducts an experiment to test the effect of a new cholesterol medication. The company selects 15 subjects randomly from a larger population. Each subject is randomly assigned to one of three treatment groups. Within each treatment group, subjects receive a different dose of the new medication. In Group 1, subjects receive 0 mg/day; in Group 2, 50 mg/day; and in Group 3, 100 mg/day. After 30 days, doctors measure the cholesterol level of each subject. The results for all 15 subjects appear in the table below: Dosage Group 1 Group 2 Group 3 O mg 50 mg 100 mg 210 210 180 240 240 210 270 250 220 270 270 210 300 270 240 (a) Perform an appropriate test to test whether there are differences among the mean cholesterol level by three different doses of the new medication at 5% level of significance. (b) Compute the p-value and indicate whether it leads to the same conclusion.arrow_forwardSome commercial airlines recirculate about half the air in the cabin during flights as a way to improve fuel efficiency. Other airlines make a policy of NOT recirculating the air and instead, have fresh air from the atmosphere constantly being inserted into the cabin with the “old” air being pumped out of the plane. A total of 1100 passengers flying from San Francisco to Denver were used for an experiment. After their flight, they were each given a list of symptoms associated with the common cold. They were asked to report if they experienced cold symptoms within 24 hours of the flight landing. Of the 517 passengers who flew on planes that recirculate the air, 108 reported post-flight cold symptoms. Of the 583 passengers who flew on airlines that do not use recirculation in the cabin, 110 reported symptoms. Suppose now that we want to use the recirculation of air data to explore “Goal #2”, which is to resolve a hypothesis test about . a) If we want to resolve this hypothesis…arrow_forward
- A study shows that 80% of the population was vaccinated against the Venusian flu but 2% of the vaccinated population got the flu anyway. If 10% of the total population got this flu, what percent of the population either got the vaccine or got the disease?arrow_forwardTo determine whether talking to plants affects their health, a researcher conducts a study in which he talks to one group of five plants and does not talk to the second group of five plants. After two weeks, he records the number of blooms produced by each plant (the dependent measure of their health). The researcher finds that, on average, the five plants he talked to produced 4.3 blooms (SD = 2.2), while the five plants he did not talk to produced 3.2 blooms (SD = 2.0). (a) Perform an independent-samples t-test to determine whether talking to the plants significantly affected their health.arrow_forwardA clinical psychologist wants to test the effectiveness of three new therapies that have been developed for reducing anxiety symptoms. The researcher recruits 15 participants and randomly assigns them to take part in Therapy A, Therapy B, or Therapy C for a month. At the end of the month, the researcher measures the participants' anxiety symptoms on a scale from 1 to 10 (where a higher score means more anxiety symptoms). The participants' scores are shown below: What is the appropriate test to use ? 3. What are the null and alternative hypotheses ? 4. Using a two-tailed alpha of .05, determine what the critical value is 5. Calculate the test statistic 6. State whether you reject or fail to reject the null hypothesis for the omnibus test 7. Calculate and report the effect size for the omnibus test 8. Perform a Post-Hoc Test. Report the significance of each pairwise comparisonarrow_forward
- You're a quality engineer at Norman's fouth largest cracker factory. where there are two production lines (A, which produces 20% of cracker boxes, and B which produces the rest). If a line produces more than one defective box in an eight -hour day, a maintenance check on the line is performed. Line A produces an average of 0.061 box defects PER Hour. Given that you're only looking at a line A, what is the probability that you will need a request a maitenance check.arrow_forwardCan pleasant aromas help a student learn better? Hirsch and Johnston, of the Smell & Taste Treatment and Research Foundation, Chicago, asked subjects to work through a set of two pencil and paper mazes six times; three times while wearing a floral-scented mask and three times with an unscented mask. Testers measured the length of time it took subjects to complete each of the six trials. The improvement in completion times, expressed as the percentage change in speed of completion from the first trial to the third trial for each maze, was recorded. (Negative values indicate no improvement with completion times longer for the third trial.) The data are attached. The researchers wanted to determine whether there was more of an improvement in completion times, on average, when wearing a floral-scented mask. (a) Clearly indicate why a paired t-test should be used in this analysis. (b) What would be the appropriate hypotheses for this test? Explain any symbols used. (c) Produce the…arrow_forwardA pharmaceutical company conducts an experiment to test the effect of a new cholesterol medication. The company selects 15 subjects randomly from a larger population. Each subject is randomly assigned to one of three treatment groups. A balanced design is used. Within each treatment group, subjects receive a different dose of the new medication. In Group 1, subjects receive 0 mg/day; in Group 2, 50 mg/day; and in Group 3, 100 mg/day. After 30 days, doctors measure the cholesterol level of each subject. The results for all 15 subjects appear in the table below: 0 mg/day 50 mg/day 100 mg/day Average Cholesterol 258 246 210 Cholesterol Variance 1170 630 450 What is the computed value of the F test statistic for the standard CRD by one-way ANOVA? Final answer to 2 decimal places.arrow_forward
- Solve the problem. A drug company developed a honey-based liquid medicine designed to calm a child's cough at night. To test the drug, 105 children who were ill with an upper respiratory tract infection were randomly selected to participate in a clinical trial. The children were randomly divided into three groups - one group was given a dosage of the honey drug, the second was given a dosage of liquid DM (an over-the- counter cough medicine), and the third (control group) received a liquid placebo (no dosage at all). After administering the medicine to their coughing child, parents rated their children's cough diagnosis as either better or worse. The results are shown in the table below: Diagnosis Treatment Better Worse Total Control 4 33 37 DM 12 21 33 Honey 24 11 35 Total 40 65 105 In order to determine whether the treatment group is independent of the coughing diagnosis, a two-way chi-square test was conducted. Calculate the value of the test statistic for the desired analysis. O x?…arrow_forwardA pharmaceutical company tested the impact of four cholesterol-reducing medications (denoted A, B, C and D) on people at high risk of heart attack. For this clinical trial 20 volunteers with LDL (bad) cholesterol levels of 140 mg/dl were randomly assigned to one of the four medications. The subjects were instructed to take one tablet per day for a period of three months after which their LDL levels were again measured. Below are the amounts (in mg/dl) by which the LDL levels decreased after the three month trial. | Medication A | Medication B | Medication C Medication D 31 30 31 30 32 31.5 32 35 29 30.5 29.75 27 33 30.5 31.75 31 29 31.5 33 29 (a) Write an appropriate statistical model (to represent the responses using an appro- priate equation) to describe the above data. Describe all symbols/notations used in the model. (b) Estimate the (four) group means, overall mean, and error variance (²) from the data. (c) Do the data provide sufficient evidence to indicate that at least one of…arrow_forwardA 2009 study shpwed that handling money reduces the perception of pain. Two groups of participants were asked to participate in a manual dexterity study. Half of the participants were given a stack of blank pieces of paper to count and the other half were given money to count. After the counting task, the participants were asked to dip their hands in 122 degree Farenheit water and rate how uncomfortable it was . The following data shows ratings of pain similar to the results obtained in the study. Counting Money Counting Paper 7 9 8 11 10 13 6 10 8 11 5 9 7 15 12 14 5 10 A. based on the sample data, does the treatment, does the treatment have a significant effect? Test with a=.01. ( make sure you have ALL the steps involved in a hypothesis test). B. Calculate Cohens d to estimate the effect size. C. What a sentence describing the outcome of the hypothesis test and the measure of effect size as it would appear on a research report.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
MATLAB: An Introduction with ApplicationsStatisticsISBN:9781119256830Author:Amos GilatPublisher:John Wiley & Sons Inc
Probability and Statistics for Engineering and th...StatisticsISBN:9781305251809Author:Jay L. DevorePublisher:Cengage Learning
Statistics for The Behavioral Sciences (MindTap C...StatisticsISBN:9781305504912Author:Frederick J Gravetter, Larry B. WallnauPublisher:Cengage Learning
Elementary Statistics: Picturing the World (7th E...StatisticsISBN:9780134683416Author:Ron Larson, Betsy FarberPublisher:PEARSON
The Basic Practice of StatisticsStatisticsISBN:9781319042578Author:David S. Moore, William I. Notz, Michael A. FlignerPublisher:W. H. Freeman
Introduction to the Practice of StatisticsStatisticsISBN:9781319013387Author:David S. Moore, George P. McCabe, Bruce A. CraigPublisher:W. H. Freeman
MATLAB: An Introduction with Applications
Statistics
ISBN:9781119256830
Author:Amos Gilat
Publisher:John Wiley & Sons Inc
Probability and Statistics for Engineering and th...
Statistics
ISBN:9781305251809
Author:Jay L. Devore
Publisher:Cengage Learning
Statistics for The Behavioral Sciences (MindTap C...
Statistics
ISBN:9781305504912
Author:Frederick J Gravetter, Larry B. Wallnau
Publisher:Cengage Learning
Elementary Statistics: Picturing the World (7th E...
Statistics
ISBN:9780134683416
Author:Ron Larson, Betsy Farber
Publisher:PEARSON
The Basic Practice of Statistics
Statistics
ISBN:9781319042578
Author:David S. Moore, William I. Notz, Michael A. Fligner
Publisher:W. H. Freeman
Introduction to the Practice of Statistics
Statistics
ISBN:9781319013387
Author:David S. Moore, George P. McCabe, Bruce A. Craig
Publisher:W. H. Freeman
Matrix Factorization - Numberphile; Author: Numberphile;https://www.youtube.com/watch?v=wTUSz-HSaBg;License: Standard YouTube License, CC-BY