Define multiple correlation. In a trivariate distribution X₁, X₂, and X3, the simple correlation coefficients are given as r₁₂= 0.5, r₂₃=0.6 and r₁₃=0.7. Find

i. partial correlation coefficient between X₁ an X₂ keeping X₃ constant.

ii. multiple correlation coefficient assuming X₁ as dependent variable.