This is a long answer, give reasoning/calculations.

A real-valued response variable y has n = 101 observations with an unbiased sample variance of 3.75 - a regression analysis has produced a residual sum of squares (RSS) of 125. Based on these values, what would the R2 be of this regression? If we assumed this regression was done with a single predictor x, what value would we obtain for the correlation xy between the predictor and response?