A researcher plans to conduct a research study comparing two treatment conditions with a total of 20 scores in each treatment. Which of the following designs would require only 20 participants? a. independent-samples design b. matched-subjects design c. between-subjects design d. within-subjects design

Which method II? Which of the following scenariosshould be analyzed as paired data?a) Spouses are asked about the number of hours of sleepthey get each night. We want to see if husbands getmore sleep than wives.b) 50 insomnia patients are given a placebo and 50 aregiven a mild sedative. Which subjects sleep more hours?c) A group of college freshmen and a group of sophomoresare asked about the quality of the university cafeteria. Dostudents’ opinions change during their time at school?

Suppose you work as a manager for a large clothing store. You are considering introducing a loyalty program to encourage customers to spend more at your store. Before rolling out your program to the public, you want to do a small experiment to estimate its effectiveness. You offer the loyalty program to 10 random customers, and also observed the sales of 27 random customers who did not get the program as a control group. The customers that were part of the loyalty program had average monthly sales of $302.57 and a sample standard deviation of $49.73. For the control group, the customers had an average monthly sales of $231.65 and a sample standard deviation of $67.88. * Given a 95% confidence interval critical value of t = 2.04, what is the upper bound (upper end) of a 95% confidence interval for the difference between two averages? Use (μloyalty program no loyalty program) for the order. Note: 1- Only round your final answer. Round your final answer to two decimal places.

Rhino viruses typically cause common colds. In a test of the effectiveness of echinacea, 42 of the 48 subjects treated with echinacea developed rhinovirus infections. In a placebo group, 93 of the 109 subjects developed rhinovirus infections. Use a 0.01 significance level to test the claim that echinacea has an effect on rhinovirus infections. Complete parts (a) through (c) below.

Identify whether the studies described here are based on (1) single samples, (2) paired samples, or (3) independent samples.   Cardiovascular disease risk factors are compared in husbands and wives. A nutritional exam is applied to a random sample of individuals. Results are compared to the results of the whole nation. An investigator compares vaccination histories in 30 autistic schoolchildren to a simple random sample of non-autistic children from the same school district.

For each scenario listed below, determine whether the scenario represents an Independent Samples or Dependent Samples (Matched Pairs) situation by placing the appropriate letter in the box provided. a. Comparing pre-test scores before training to post-test scores: OIndependent Samples OMatched Pairs b. Comparing the number of speeding tickets received by men to the number received by women: OIndependent Samples Matched Pairs c. Comparing pain levels of a group receiving a placebo to a group receiving a medicine: Independent Samples OMatched Pairs d. Comparing pain levels before and after treatment with magnetic therapy: Independent Samples OMatched Pairs

Why is a cohort design more efficient than a case-control design to study a rare exposure?  (Select one best answer)   Group of answer choices a. Subjects are selected based on their exposure status. b. Subjects are selected based on their disease status. c. Subjects are selected based on their exposure and disease status. d. Subjects are selected based on their random allocation to treatment or placebo. e. None of these.

An experiment to determine the most effective way to teach safety principles applied four different teaching methods. Some employees were given programmed instruction booklets and worked through the course at their own pace. Other employees attended lectures. A third group watched a television presentation, and a fourth group was divided into small discussion groups. A high of 10 was possible. A sample of five tests was selected from each group. The test grade results were:  Sample Number Programmed Instruction Lecture TV Group Discussion 1 6 8 7 8 2 7 5 9 5 3 6 8 6 6 4 5 6 8 6 5 6 8 5 5 At the 0.01 level, what is the critical value?   Multiple Choice   1.00   1.96   3.24   5.29

Acne is a common skin disease that affects most adolescents and can continue into adulthood. A study compared the effectiveness of three acne treatments and a placebo, all in gel form, applied twice daily for 12 weeks. The study's 517 teenage volunteers were randomly assigned to one of the four treatments. Success was assessed as clear or almost clear skin at the end of the 12 week period. The results of the study can be seen in the table below. Using the appropriate statistical test, determine if there is significant evidence that the four treatments perform differently. If so, how do they compare.

Part 3: Read each of the following studies, construct the appropriate 2x2 table, calculate the measure of association, state the study design, and state the interpretation of the results. 1. An investigator wanted to determine whether playing video games constantly (chronic videogamer: CVG) was associated with carpal tunnel syndrome (CTS). By interviewing males ages 15-30 in a Midwestern city, the researchers located 400 males with CTS. A total of 800 additional males without CTS were selected at random and interviewed. Of those with CTS, 59 reported not being a CVG. 465 control males reported being a CVG. Construct the appropriate 2x2 table and calculate the odds ratio between chronic videogaming and carpal tunnel syndrome. 2x2 table Odds Ratio Predictions: On Accessibility: Investigate O E 99+ 37M3H I Focus 44°F @¹ 7 10/