8. In a repeated-measures study, the average difference (D-bar) between dependent variable (DV) scores before and after treatment is 8.00. The sample size (N) is 10. The estimate of the standard error (the error estimate) is 2.45. Calculate the df______ - compute tobs, find tcritical ______ (for a two-tailed test, p is set at less than .05).

Based on the information for #8, the logic dictates a decision to:

a. reject the null hypothesis (H: D-bar = 0)

b. fail to reject the null hypothesis (Ho: D-bar = 0)