Why is it possible to show a cause-and-effect relationship between two variables using an experiment and not an observational study? (A) Unlike observational studies, experi- ments can be double-blinded. (B) Unlike observational studies, experi- ments control for confounding variables. (C) Unlike observational studies, experi- ments can be blocked. (D) Experiments tend to be conducted with more care for details than observational studies. (E) Experiments tend to use larger sample sizes than observational studies.

Why is it possible to show a cause-and-effect relationship between two variables using an experiment and not an observational study? (A) Unlike observational studies, experi- ments can be double-blinded. (B) Unlike observational studies, experi- ments control for confounding variables. (C) Unlike observational studies, experi- ments can be blocked. (D) Experiments tend to be conducted with more care for details than observational studies. (E) Experiments tend to use larger sample sizes than observational studies.

Name: 3. Why is it possible to show a cause-and-effectrelationship between
Uploaded: 2024-03-20T07:07:37.000Z
Channel: Bartleby
Description: 3. Why is it possible to show a cause-and-effectrelationship between two variables using anexperiment and not an observational study?(A) Unlike observational studies, experi-ments can be double-blinded.(B) Unlike observational studies, experi-ments

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

See similar textbooks

Similar questions

1) When the effect of one variable depends on the level of other variable , that is call the main effect True or false 2) When an interaction term is statistically significant , you must be cautious in interoreting the main effects . True or false give above answer and explain ?
When an interaction term is statistically significant, you must be cautious in interpreting the main effects. True or False?
The article "Americans are 'Getting the Wrong Idea' on Alcohol and Health"† reported that observational studies in recent years that have concluded that moderate drinking is associated with a reduction in the risk of heart disease may be misleading. The article refers to a study conducted by the Centers for Disease Control and Prevention that showed that moderate drinkers, as a group, tended to be better educated, wealthier, and more active than nondrinkers. Explain why the existence of these potentially confounding variables prevents drawing the conclusion that moderate drinking is the cause of reduced risk of heart disease. (Select all that apply.) Someone who is more active is more likely to avoid healthier food. Someone who is wealthier is more likely to purchase healthier food. Someone who is more active is more likely to seek out healthier food. Someone who is educated is more likely to seek out healthier food. Someone who is educated is more likely to not be aware of what…
The article "Americans are 'Getting the Wrong Idea' on Alcohol and Health"† reported that observational studies in recent years that have concluded that moderate drinking is associated with a reduction in the risk of heart disease may be misleading. The article refers to a study conducted by the Centers for Disease Control and Prevention that showed that moderate drinkers, as a group, tended to be better educated, wealthier, and more active than nondrinkers. Explain why the existence of these potentially confounding variables prevents drawing the conclusion that moderate drinking is the cause of reduced risk of heart disease. (Select all that apply.) a. Someone who is more active is more likely to avoid healthier food. b.Someone who is more active is more likely to seek out healthier food. c. Someone who is wealthier is more likely to purchase healthier food. d.Someone who is educated is more likely to seek out healthier food. e.Someone who is educated is more likely to not be aware…
Does posting calorie content for menu items affectpeople’s choices in fast-food restaurants? According to results obtained by Elbel, Gyamfi, and Kersh(2011), the answer is no. The researchers monitoredthe calorie content of food purchases for children andadolescents in four large fast-food chains before andafter mandatory labeling began in New York City. Although most of the adolescents reported noticing thecalorie labels, apparently the labels had no effect ontheir choices. Data similar to the results obtained showan average of M = 786 calories per meal with s =85 for n =100 children and adolescents before thelabeling, compared to an average of M = 772 calorieswith s = 91 for a similar sample of n = 100 after themandatory posting.a. Use a two-tailed test with a = .05 to determinewhether the mean number of calories after theposting is significantly different than before caloriecontent was posted.b. Calculate r2to measure effect size for the mean difference.
Recently, the Shine research clinic published a report stating that the regular application of a very popular sunscreen lotion NoHelios might cause some forms of skin cancer. The manufacturer of NoHelios issued an energetic counterstatement asserting that the Shine clinic's conclusions were statistically inconsistent. Wellbeing pharmacy chain has been selling NoHelios lotion for a long time. The market research department of Wellbeing wants to see what is currently happening with NoHelios lotion demand. The members of a random sample of customers were asked about their willingness to use NoHelios before and after the publication of Shine clinic's report. The answers were provided in form of a score from 0 to 10 (higher score means more willingness). Results for five customers are shown in the following table. The "before" score is matched to the "after" score, and the difference should be calculated. Suppose that it is known that such differences have approximately bell-shaped…
If the correlation between two quantitative variables becomes stronger and closer to 1, then we have stronger evidence that there is a causative relationship between the two variables. TRUE or FALSE?
Recently there has been quite a bit of controversy about the lack of definitive knowledge about the adverse side effects associated with hormone based birth control usage. Suppose a researcher is interested in the effects of birth control in women aged 18-25 relevant to blood pressure. The researcher assumes that women in this demographic that are taking hormone based birth control are at risk for increased blood pressure. Assume the following table contains the summary statistics of two SRSs, one from a cohort of women taking hormone based birth control, and one from a cohort of women birth control free. Study Arm Average Systolic BP Sample Standard Deviation Sample Size Birth Control 124 6.8 246 No BC 116 4.3 267 a) Carry out the appropriate statistical procedure to determine if there is a significant difference in the systolic blood pressure between the two groups of women and write out a null and alternative hypotheses. (Use an alpha level of 0.05) b) Construct a 95%…
In ANOVA, what will be the conclusion when the means of the between groups vary from within groups? a.Accept the null hypothesis b.Reject the null hypothesis c.Conduct main effects d.Conduct interaction effects
Compared to observational studies like cohort and case-control studies, experimental studies like RCTs are better at establishing causality. True False
When results are not statistically significant, why do you conclude that it is plausible that the two variables are independent rather than concluding that the variables are different independent?
To demonstrate a causal relationship, the researchers must have appropriate time order and covariation between the variables, and they must have eliminated plausible alternative explanations. What is missing, if anything, in the following cause-and-effect assertions? Explain. A study looks at the promotion time for women and concludes that women face barriers to promotions. Proponents of free college education for all argue that teenage pregnancies and crime would be lower if everyone had the opportunity to go to college. An e-mail circulated stating that a study found that a majority of women who had breast cancer had used deodorant containing a specific chemical and argued that the government should ban that chemical.