Suppose that for a given data set

1.Suppose that for a given data set,
s2x=440,s2y=820,r=0.35,n=7

Then the regression standard error is:

Answer = 

2.Suppose that a regression yields the following sum of squares:
Σ(yi−yˉ)2=200, Σ(yi−yˆi)2=90, Σ(yˆi−yˉ)2=110

Then the percentage of the variation in y that is explained by the variation in x is:

Answer =