Finding the Third Proportional to 53,688 and 78,684

Step by Step Solution

1. Step 1: Write the proportion equation
   53,688 : 78,684 = 78,684 : x
2. Step 2: Convert to fraction form
   53,688/78,684 = 78,684/x
3. Step 3: Cross multiply
   53,688x = 78,684 × 78,684
4. Step 4: Simplify right side
   53,688x = 6,191,171,856
5. Step 5: Solve for x
   x = 6,191,171,856/53,688
6. Step 6: Final answer
   x = 115,317.61