4. Which kind of study is generally moreeffective at blocking confounders?Select one:a. Experimentb. Observational studyc. Both are equally good

Concept of confounding is important in statistical analysis.

Answered: 4. Which kind of study is generally…

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

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The International Business Society conducts a series of managerial surveys to detect challenges that international managers encounter and what strategies help them overcome those challenges. A previous study showed that employee retention is the most critical organizational challenge currently confronted by international managers. One strategy that may impact employee retention is a successful employee recognition program. The International Business Society randomly selected 423 small firms and 192 large firms. The study showed that 326 of the 423 small firms have employee retention programs compared to 167 of the 192 large organizations. At the 0.01 level of significance, is there evidence of a significant difference between small firms and large firms concerning the proportion that has employee recognition program? Find the p-value and interpret its meaning? Construct and interpret a 99% confidence interval estimate for the difference between small firms and large firms concerning…
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An advertisement firm is making a new marketing strategy and selling rates are being considered. Samples of selling rates are taken from both the existing strategy (A) and the new strategy (B) to determine if the new marketing 8 - strategy results in an improvement. If 800 of 3200 items were being sold with the existing strategy, and 365 of 1400 items are being sold with the new one. We want to test that whether the new strategy is superior to the existing one. According to the hypothesis testing, what is the correct hypothesis along with its result at 90% confidence level? a) Hypothesis: H_0: p_A=p_B: H_1: p_A> p_B: Result: Fail to reject H_0 b) Hypothesis: H_0: p_A=p_B: H_1: p_A< p_B; Result: Reject H_0 c) Hypothesis: H_0: p_A=p_B: H_1: p_A
3. A national retailer has completed an internal survey on its social media strategy. The key question in the survey is whether the stores managers think that the recently launched social media strategy is effective. The following is the output of a statistical analysis of the data: Social media Strategy is effective Store Managers No YesVancouver 40 55Manitoba 20 35Alberta 15 35 Based on this output, can the retailer conclude that the opinion of the store managers on the whether the recently launched social media strategy is effective is dependent on which region they belong to? Use a chi square test and a level of significance of 0.05
The International Business Society conducts a series of managerial surveys to detect challenges that international managers encounter and what strategies help them overcome those challenges. A previous study showed that employee retention is the most critical organizational challenge currently confronted by international managers. One strategy that may impact employee retention is a successful employee recognition program. The International Business Society randomly selected 423 small firms and 192 large firms. The study showed that 326 of the 423 small firms have employee retention programs compared to 167 of the 192 large organizations. At the 0.01 level of significance, is there evidence of a significant difference between small firms and large firms concerning the proportion that has employee recognition program? Find the p-value and interpret its meaning? Construct and interpret a 99% confidence interval estimate for the difference between small firms and large firms concerning…
In 2018, a consumer goods giant had more than 20 brands with more than $1 billion in annual sales. How does the company create so many successful consumer products? They effectively invests in research and development to understand what consumers want. One method used to determine consumer preferences is called conjoint analysis. Conjoint analysis allows a company to ascertain the utility that a respondent in the conjoint study places on a design of a given product. The higher the utility, the more valuable a respondent finds the design. Suppose we have conducted a conjoint study and have the following estimated utilities (higher is preferred) for each of three different designs for a new whitening toothpaste. Respondent Utilities Design A Design B Design C 1 24.6 34.4 28.8 2 31.4 31.4 33.9 3 31.8 20.2 27.8 4 15.4 26.4 25.1 5 20.7 18.3 18.2 6 41.0 34.0 44.8 7 27.1 22.5 27.3 8 20.2 21.8 27.9 9 31.6 29.4 31.3 10 24.4 29.0 29.3 At the 0.05 level of…
2. In a study of jury behavior, two samples of participants were provided details about a trial in which the defendant was obviously guilty. Although group 2 received the san details as group 1, the second group was also told that some evidence had been withheld from the jury by the judge. Later, the participants were asked to recommend a jail sentence. The length of term suggested by each participant is presented here. Is there a significant difference between the two groups in their responses? For Group 1: M = 3, SS = 16, n= 8 For Group 2: M = 6, SS = 24, n = 10 %3D a. Formulate the hypotheses. b. Determine the critical value(s). c. Calculate the test statistic.
Two ad agencies want to understand issues that are important to students. Agency A will interview 50 students whose names are randomly chosen from school enrollment data. Agency B will interview 50 randomly selected people from those who respond to a social media posting. Which method will produce a fair sample of the student population and why? Agency A, because students are convenient and easy to interview Agency A, because names randomly selected from school data will be student names Agency B, because people who respond to social media postings have strong opinions Agency B, because people who respond to social media postings are usually students
2.
A doctor wanted to study the effect of four different treatments on mental health. A group of 100 adults experiencing depression volunteered for the study. The doctor randomly assigned one-fourth of them to each of four groups. Group 1 followed a specific exercise plan, group 2 followed a specific diet plan, group 3 followed an exercise and diet plan, and group 4 did not follow any plan. After 4 weeks, the doctor contacted each participant and asked them if they felt any better. The results are displayed in the table. The doctor would like to know if these data provide convincing evidence that the distribution of responses differs across the treatment groups in the population of all patients like these. The random condition is met. The 10% condition is not needed because random sampling did not take place. This table of expected counts shows that all expected counts are at least 5. What is the value of the chi-square test statistic? χ‑2 = 5.03 χ‑2 = 6.26 χ‑2 = 25.33 χ‑2 = 39.22

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4. Which kind of study is generally more effective at blocking confounders?