A study was performed looking at the effect of physical activity on cognitive
Table 8.23 Mean difference from baseline (18-month score minus baseline score) among participants with mild cognitive impairment in the ADAS-Cog score*
*A negative change indicates improvement since high values on the testindicate worse cognitive function
What is the standard deviation of change in the control group?
Want to see the full answer?
Check out a sample textbook solutionChapter 8 Solutions
WebAssign for Rosner's Fundamentals of Biostatistics, 8th Edition [Instant Access], Single-Term
- What is meant by the sample space of an experiment?arrow_forwardWhat is an experiment?arrow_forwardA clinician was interested in exploring functionality in patients following a stroke rehabilitation program. Participants were recruited through the rehabilitation unit at Providence Care Hospital. Functional status was evaluated at baseline (immediately following stroke), and 8 weeks later. Patients’ functional outcomes were rated on the following 5-point scale: 1 – poor, 2- fair, 3 – moderate, 4 -good, 5 – excellent. The clinician wants to know whether patients improved their functioning over the 8-week period. 1. Under the heading “Results” present your findings (i.e., what you found).Include at least one measure of central tendency and variability. An assumption check(describe what you did and what you found, as needed), check for potential outliers,and present the findings of your inferential test (i.e., your critical value and p value), asappropriate. Patient Baseline Functional Status (1 to 5) 8 week follow up functional status (1 to 5) 1 4 3 2 1 2 3 3 3 4 5 4 5 4 1…arrow_forward
- Many people take ginkgo supplements advertised to improve memory. In a study, elderly adults were assigned to the treatment group or control group. The 104 participants who were assigned to the treatment group took 40 mg of ginkgo 3 times a day for 6 weeks. The 115 participants assigned to the control group took a placebo pill 3 times a day for 6 weeks. At the end of 6 weeks, the Wechsler Memory Scale was administered. Higher scores indicate better memory function. Summary values are below in the table. n Ginkgo 104 5.7 0.6 Placebo 115 5.5 0.5 We are testing for evidence that taking 40mg of ginkgo 3 times a day is effective in increasing mean performance on the Wechsler Memory Scale. Is this problem about means or proportions? Is this problem one sample or two sample? Set up the hypothesis Ho- Hại Find the test statistic (round to decimal places) Test statistic Find the p-value (round to 4 decimal places) p-value What is the degrees of freedom by calculator? (Round to the nearest whole…arrow_forwardMany people take ginkgo supplements advertised to improve memory. Are these over-the- counter supplements effective? In a study, elderly adults were assigned to the treatment group or control group. The 104 participants who were assigned to the treatment group took 40 mg of ginkgo 3 times a day for 6 weeks. The 115 participants assigned to the control group took a placebo pill 3 times a day for 6 weeks. At the end of 6 weeks, the Wechsler Memory Scale was administered. Higher scores indicate better memory function. Summary values are given in the following table: Ginkgo 104 5.7 0.6 Placebo 115 5.5 0.5 Perform the appropriate test to determine if taking 40mg of ginkgo 3 times a day is effective in increasing mean performance on the Wechsler Memory Scale. > Is the study observational or designed experiment? > Can you conclude association or causation with this type of study? > Is this a matched-pair dependent test or two-sample independent test? O Null hypothesis: OAlternative…arrow_forwardMany people take ginkgo supplements advertised to improve memory. Are these over-the- counter supplements effective? In a study, elderly adults were assigned to the treatment group or control group. The 104 participants who were assigned to the treatment group took 40 mg of ginkgo 3 times a day for 6 weeks. The 115 participants assigned to the control group took a placebo pill 3 times a day for 6 weeks. At the end of 6 weeks, the Wechsler Memory Scale was administered. Higher scores indicate better memory function. Summary values are given in the following table: N x̄ s Ginkgo 104 5.7 0.6 Placebo 115 5.5 0.5 a) Based on these results, is there evidence that taking 40mg of ginkgo 3 times a day is effective in increasing mean performance on the Wechsler Memory Scale? b) Write a brief report on your findings.arrow_forward
- One study of cell phones and the risk of brain cancer looked at a group of 469 people who have brain cancer. The investigators then asked about the use of cell phones. Result: “Our data suggest that the use of hand- held cellular phones is not associated with risk of brain cancer. B . Based on this study, can you determine that cellular use does not CAUSE brain cancer? Why or why not?arrow_forwardIn a research study, 100 college students took a personal finances class and 100 students took a personal health class (as a control condition). Two years later all participants completed a survey about their personal finances. A higher score on the survey indicated greater financial health. The mean financial health of the students who took the finance class was M = 29.7, SD = 7.8, while the mean for the other students was M = 28.8, SD = 9.1). The statistical information was t(198) = .75, p = .23, d =.11. Based on these results, which of the following is the best recommendation?" These data suggest that the intervention is not worth pursuing any further. Start considering how you might revise the intervention to make it more effective. Start making all students take a personal finance class. The data clearly indicate that it is helping to improve students' financial health 2 years later. Collect more data, you need a larger sample size before you can…arrow_forwardMany people take ginkgo supplements advertised to improve memory. Are these over-the- counter supplements effective? In a study, elderly adults were assigned to the treatment group or control group. The 104 participants who were assigned to the treatment group took 40 mg o ginkgo 3 times a day for 6 weeks. The 115 participants assigned to the control group took a placebo pill 3 times a day for 6 weeks. At the end of 6 weeks, the Wechsler Memory Scale was administered. Higher scores indicate better memory function. Summary values are given in the following table: N Ginkgo 104 5.7 0.6 Placebo 115 5.5 0.5 Perform the appropriate test to determine if taking 40mg of ginkgo 3 times a day is effective in increasing mean performance on the Wechsler Memory Scale. > Is the study observational or designed experiment? > Can you conclude association or causation with this type of study? Is this a matched-pair dependent test or two-sample independent test?arrow_forward
- A group of disabled women ages 65 and older were followed for several years. It was found that those who had a vitamin B12 deficiency were twice as likely to suffer from severe depressions than those who did not.a. Describe the type of study being performed.b. Describe the explanatory variable(s) and response variable(s).arrow_forwardThe general population of people with Major Depressive Disorder (MDD) has a known average in regards to symptom severity. These scores are measured on the Brief Depression Inventory, which uses a 0-100 scale, with higher scores indicating greater symptom severity. Researchers at Stanford select a sample of volunteers who meet MDD criteria. That sample of people participate in Cognitive Behavioral Therapy for a period of time, and their symptom severity is measured on the Brief Depression Inventory. The sample's average score is then compared to the general population average for people with MDD. Researchers find that Cognitive Behavioral Therapy appears to treat MDD fairly well! How did researchers most likely analyze their data given this experimental setup? O Single Sample T O Paired Samples T O Independent Samples T O ANOVA O Correlationarrow_forward
- Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw HillBig Ideas Math A Bridge To Success Algebra 1: Stu...AlgebraISBN:9781680331141Author:HOUGHTON MIFFLIN HARCOURTPublisher:Houghton Mifflin HarcourtCollege Algebra (MindTap Course List)AlgebraISBN:9781305652231Author:R. David Gustafson, Jeff HughesPublisher:Cengage Learning