Finding the Third Proportional to 539.63 and 860.78

Step by Step Solution

1. Step 1: Write the proportion equation
   539.63 : 860.78 = 860.78 : x
2. Step 2: Convert to fraction form
   539.63/860.78 = 860.78/x
3. Step 3: Cross multiply
   539.63x = 860.78 × 860.78
4. Step 4: Simplify right side
   539.63x = 740,947.72
5. Step 5: Solve for x
   x = 740,947.72/539.63
6. Step 6: Final answer
   x = 1,373.06