An article in Concrete Research ("Near SurfaceCharacteristics of Concrete: Intrinsic Permeablility," Vol. 41,1989), presented data on compressive strength x and intrinsicpermeability y of various concrete mixes and cures. Summaryquantities are n = 14, Σ yi =572, Σ = 23,530, Σ xi =43,Σ = 157.42, and Σxiyi= 1697.80. Assume thatthe two variables are related according to the simple linearregression model.
(a) Calculate the least squares estimates of the slope andintercept. Estimate . Graph the regression line.
(b) Use the equation of the fitted line to predict whatpermeability would be observed when the compressive strength is x =4.3.
(c) Give a point estimate of the mean permeability when compressivestrength is x = 3.7.
(d) Suppose that the observed value of permeability at x = 3.7 is y= 46.1. Calculate the value of the correspondingresidual.

Two researchers are attempting to create a new psychotherapy protocol that more reduces panic attacks. they believe that they have succeeded and are now in the clinical trial period of their protocol's development. they are working with several cohort groups, some of which have been through the new protocol, while others have done the standard protocol currently recommended. if these researchers are interested in evaluating the difference in the percentage of test subjects who successfully decreased their panic attacks in 2 months on the new protocol versus the percentage of test subjects who successfully decreased their panic attacks in 2 months with the traditional protocol, which of the following statistical tests would be most appropriate? a. analysis of variance (anova) b. correlation c. chi-square test d. paired t-test e. independent t-test