Finding the Third Proportional to 647.16 and 1,385.86

Step by Step Solution

1. Step 1: Write the proportion equation
   647.16 : 1,385.86 = 1,385.86 : x
2. Step 2: Convert to fraction form
   647.16/1,385.86 = 1,385.86/x
3. Step 3: Cross multiply
   647.16x = 1,385.86 × 1,385.86
4. Step 4: Simplify right side
   647.16x = 1,920,606.21
5. Step 5: Solve for x
   x = 1,920,606.21/647.16
6. Step 6: Final answer
   x = 2,967.76