A researcher fails to find a significant difference in mean blood pressure in 36 matched pairs. The test was carried out with a power of 85%. Assuming that this study was well designed and carried out properly, do you believe that there really is no significant difference in blood pressure?  Explain

Researchers at the Mayo Clinic have studied the effect of sound levels on patient healing and have found a significant association (louder hospital ambient sound level is associated with slower postsurgical healing). Based on the Mayo Clinic's experience, Ardmore Hospital installed a new vinyl flooring that is supposed to reduce the mean sound level (decibels) in the hospital corridors. The sound level is measured at five randomly selected times in the main corridor.  New Flooring Old Flooring 42 48 41 51 40 44 37 48 44 52       Click here for the Excel Data File (a-1) Does the evidence convince you that the mean sound level has been reduced? Select the appropriate hypotheses. a. H0: μ1 − μ2 ≤ 0 vs H1: μ1 − μ2 > 0b. H0: μ1 − μ2 ≥ 0 vs H1: μ1 − μ2 < 0 multiple choice 1 a b  (a-2) At α = .05, what is the decision rule? Assume unequal variances. Use the quick rule for degrees of freedom. a. Reject the null hypothesis if tcalc < −1.86 (8 df.)b. Reject…

Ninety nine percent of scores fall between 3 and -3 standard deviations from the mean.  True or False?

For each case below, state what type of statistical test you would use to analyze each dataset. Explain your answer! Hemoglobin is a protein responsible for carrying oxygen throughout your blood stream. Blood hemoglobin levels in humans average at about 14.5g/dL. We are interested in whether a sample of 20 iron deficient individuals have lower blood hemoglobin levels compared to the general population. The average hemoglobin level for our sample is 10.9g/dL, with an estimated population standard deviation of 1.92g/dL. A researcher is looking at whether the time it takes for rats to relearn how to run a maze decreases after they’ve been exposed to the maze more than once. Using 15 rats, he measures how quickly they are able to successfully run a maze at two different times points: once when they are first exposed to the maze, and again after they’ve run the maze three times.  A social psychologist is curious about whether social rejection increases aggression in narcissists. He…