11) In a study to help individuals quit smoking, investigators randomly assigned participants to one oftwo groups. In Group A, participants took a class to quit smoking. The classes took place each weekfor 10-weeks and included information about the benefits of quitting smoking. In addition,participants in the class received strong social support from mentors or "buddies." In the Group B,participants read a 3-page pamphlet created by the American Cancer Association that explains thebenefits of quitting smoking. The investigator randomly assigned participants to one of the twogroups. It was found that those who participated in the class and received support from theirbuddies were more likely to quit smoking compared to those in the other group that received onlythe pamphlet.a) Why was random assignment used in this study?b) What conclusion can we draw from this experiment that we wouldn't be able to draw ifparticipants were allowed to choose whether they had a support group or read a 3-pagepamphlet?

Given In a study to help individuals quit smoking, investigators randomly assigned participants to…

Answered: 11) In a study to help individuals quit…

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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A company wishes to evaluate the effect of package design on one of its products, a certain brand of cereal. The four package designs are to be tested in different stores throughout a large city. There are 20 stores available for the study. The amount of cereal sold is known to vary depending on the size of the stores. The 20 stores are divided into five groups of four stores each by size. The following sales figures ($1000s) were obtained after a 1-month period. Stores Design A Design B Design C Design D 1 40 33 37 38 2 45 27 32 40 3 43 31 30 41 4 44 38 40 42 5 56 45 49 42 Enter the above data into a suitable software and then conduct an analysis of variance without blocking to test whether there is evidence of a significant difference in mean sales of different package designs. Use alpha=0.01. What is the conclusion for the null hypothesis that all treatment means are equal? O Do not reject HO. There is sufficient evidence to conclude that the average sales for all stores are not…
A company wishes to evaluate the effect of package design on one of its products, a certain brand of cereal. The four package designs are to be tested in different stores throughout a large city. There are 20 stores available for the study. The amount of cereal sold is known to vary depending on the size of the stores. The 20 stores are divided into five groups of four stores each by size. The following sales figures ($1000s) were obtained after a 1-month period. Stores Design A Design B Design C Design D 1 40 33 37 38 2 45 27 32 40 3 43 31 30 41 4 44 38 40 42 5 56 45 49 42 Enter the above data into a suitable software and then conduct an analysis of variance with blocking (analyze this data as a complete block design) to test further whether there is evidence of a significant difference in mean sales of different package designs. Use alpha=0.01. What are the sums of squares for Blocks? Provide your answer to the nearest 2 decimal places.
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Suppose you want to study the effectiveness of calculators in College math classrooms by giving subset of the students in each classroom calculators. Would you use an experimental or observational study? and why?
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Mandrake Falls High School is providing a weekend course in laboratory techniques to its laboratory students. Of the 200 students enrolled in lab classes at Mandrake, 75 have taken the weekend course. Mandrake is evaluating the course's effectiveness by having its lab instructors record harmful lab "incidents": accidents, misuse of lab equipment, etc. The contingency table below gives a summary of the data that have been gathered so far for Mandrake's 200 lab students. Each student is classified according to two variables: status regarding lab techniques course ("Took the course" or "Didn't take the course") and laboratory performance ("Involved in no incident", "Involved in exactly one incident", or "Involved in 2+ incidents"). In the cells of the table are the respective observed frequencies. Note that three of the cells also have blanks. Fill in these blanks with the frequencies expected if the two variables, status regarding lab techniques course and laboratory performance, are…
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In a survey of working parents (both parents working), one of the questions asked was "Have you refused a job, promotion, or transfer because it would mean less time with your family?" Two hundred men and 200 women were asked this question. Twenty-nine percent of the men and 24% of the women responded "yes." a. Based on this survey, can we conclude that there is a difference in the proportion of man and women responding “yes" at the 0.05 level of significance? (i) State the null and alternative hypotheses (ii) What test statistics would you use and why? (iii) Compute the value of the test-statistic. (iv) What rejection region would you use? (v) State your conclusion in the context of the problem. b. What P-value is associated with this test? Based on this P-value, could H. be rejected at significance level 0.08? c. Find a 95% confidence interval for the difference between the proportion of men and women responding "yes." Based on this confidence interval, would your conclusion be the…
Would observations or interviews be more appropriate to research the following topic?How veterans find employment after exiting military service.O ObservationsO Interviews
please answer. thanks!
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