For the following, specify which descriptive and inferential procedures should be performed, explain what is being compared, and identify the key to answering the researcher’s question.
(a) A researcher measures a group of participants using standard tests of “social nervousness” and “introversion” to determine if introversion is a good predictor of nervousness. (Scores are interval scores.)
(b) The average worker at a calculator plant can assemble 106 calculators in his or her first hour of work. During their final hour, a sample of workers produced an average of only 97.4 calculators (sX = 17.3). Should we conclude that performance decreases during the final hour for all workers?
(c) For 20 years the basketball coach recorded his team’s performance when making free throws, with µ = 71.1 and σX = 14.2. A sports psychologist trained 20 players on this year’s team to visualize each shot beforehand. They shot an average of 77.6 for the year. Is visualization a way to improve the performance of all players?