The mean proportion of b3a2 and 4a39b2.Formula used:Mean proportion between two values x and y=x×yCalculations:Let x=b3a2 and y=4a39b2.⇒ Mean proportion =b3a2×4a39b2⇒ Mean proportion =b3×4a3a2×9b2⇒ Mean proportion =4×b3×a39×b2×a2⇒ Mean proportion =49×b3b2×a3a2⇒ Mean proportion =49×b1×a1⇒ Mean proportion =4×a×b9⇒ Mean proportion =4×a×b9⇒ Mean proportion =2ab3