1. Ignore the \"Question 1\" beside the Table 3.18. Which result is statisticall
ID: 3236884 • Letter: 1
Question
1. Ignore the "Question 1" beside the Table 3.18. Which result is statistically significant or not for each of the four weeks?
2. What does this exercise have to say about the relationship between sample size and statistical significance? Be very specific in your answer.
3. What does this exercise have to say about whether one can reliably infer practical significance from statistical significance?
EXHIBIT 2 The N Crowd An MD/Ph.D at a major research institution is studying a new cannabis-based pain medication. The patients who volunteer for the study are randomly divided into two groups. Group 1 is given a placebo (Treatment 1). After one hour, group members rate the effectiveness of the pain relief on a scale of 1 to 100. Group 2 is given effectiveness in a similar way. Initially, only 25 volunteers were available for each group. By the end of the month, however, there were 25,000 volunteers in each group, making this the largest clinical trial in recent memory. Amazingly, there is only a one-point difference between the ratings of the placebo group and the ratings of the active treatment group at each stage. Formally, the following choice has to be made: Ho: Treatment 2 is no different than Treatment 1 H.: Treatment 2 is than Treatment TABLE 3.18 Statistically significant Results Questions 4th 3rd 2nd 1. Help the researcher decide if her 1st Week Week Week Week results are statistically significant each week by filling out the last two rows Sample size in 250 2,500 25,000 25 of Table 3.18. The researcher adopted each group (N) an alpha level of 0.05. Unless your Standard deviation 20 20 20 20 instructor tells you otherwise, you in each group may use the convenient GRAPHPAD BO SO Treatment 1 mean applet to complete your calculations. (placebo) This applet is available at: http:// 5I 5I www.graphpad.com/quickcalcs/ Treatment 2 mean (new drug) ttest1/?Format SD. The first table 0.430 entry has already been filled out, but p-value you may want to use that answer to make sure that you understand the Statistically significant? 0 Yes 0 Yes O Yes 0 Yes Check 'Yes' or 'No' No No 0 No O No processExplanation / Answer
1:
Since p-values for the 3rd and 4th week are less than 0.05 signifcance level so results of 3rd week and 4th week are signficant. That is for these weeks we cannot conclude that "Treatment 2 is no different than treatment 1".
2:
As the sample size increases, the chances of signifcant results also increases.
As the sample size increases, test statistics value is also increases. So chances of rejecting the null hypothesis also increases.
3:
We can rely on inference if sample size is not too small and it is randomly taken from the whole populaiton under study.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.