The article Some Field Experience in the Use of anAccelerated Method in Estimating 28-Day Strengthof Concrete (J. of Amer. Concrete Institute, 1969:895) considered regressing y 5 28day standard-curedstrength (psi) against x 5 accelerated strength spsid.Suppose the equation of the true regression line isy 5 1800 1 1.3xa. What is the expected value of 28-day strength whenaccelerated strength 5 2500?b. By how much can we expect 28-day strength tochange when accelerated strength increases by 1 psi?c. Answer part (b) for an increase of 100 psi.d. Answer part (b) for a decrease of 100 psi.

Tuesday, April 11 h • Example 5: Smiles and Leniency (skip for today) A study examined the effect of a smile on the leniency of disciplinary action for wrongdoers. Participants in the experiment took on the role of members of a college disciplinary panel judging students accused of cheating. For each accused student, along with a description of the offense, a picture was provided with either a smile (n = 34)1 or a neutral facial expression (n = 34). A leniency