A researcher plans to conduct a test of hypotheses at the α=0.05 significance level. She designs her study to have a power of 0.80 at a particular alternative value of the parameter of interest. 18. The probability that the researcher will commit a Type I error is a. 0.05. b. 0.20. c. 0.80. d. equal to the P-value and cannot be determined until the data have been collected. 19. The probability that the researcher will commit a Type II error for the particular alternative value of the parameter at which she computed the power is a. 0.05. b. 0.20. c. 0.80. d. equal to the 1 – (P-value) and cannot be determined until the data have been collected. 20. The appraised values of three recently sold houses in the Columbus area are (in thousands of dollars) 160, 215, and 195. The standard error of the mean of these three appraised values is a. 190.00. b. 27.84. c. 22.73. d. 16.07.