Exam 1

1. Metainformation

   Tag	Value
   file	Inferential_Statistics_uu-power-845-nl_uu-power-845-nl
   name	uu-power-845-nl
   section	Inferential Statistics/NHST/Power
   type	schoice
   solution	FALSE, TRUE, FALSE, FALSE
   Type	Calculation
   Program	SPSS
   Language	Dutch
   Level	Statistical Literacy

   Question

   We are interested in evaluating the effect of a natural product on reducing blood pressure. This is done by comparing the mean reduction in blood pressure of a treatment (natural product) group and a placebo group using a two-sample t test. The standard deviations are approximately the same, so the researchers will use an independent samples t test, and based on previous work the researchers are able to specify a common sample standard deviation. The researchers have specified $\mu_{1}$ – $\mu_{2}$ = 7 as an alternative they would like to be able to detect with a significance level of 1%. Sample sizes of 50 in each group are selected and found to have a power of 80%. If the researchers now decide they are interested in the alternative $\mu_{1}$ – $\mu_{2}$ = 5 instead, how would the power of the study for this alternative compare to the previous one?

   
   
   1. FALSE: It would be greater than 80%.
   2. TRUE: It would be less than 80%.
   3. FALSE: It could be either less than or greater than 80%, depending on whether the natural product is effective.
   4. FALSE: It could be either less than or greater than 80%, depending on the standard deviation.