Finding the Third Proportional to 53,142 and 78,687

Step by Step Solution

1. Step 1: Write the proportion equation
   53,142 : 78,687 = 78,687 : x
2. Step 2: Convert to fraction form
   53,142/78,687 = 78,687/x
3. Step 3: Cross multiply
   53,142x = 78,687 × 78,687
4. Step 4: Simplify right side
   53,142x = 6,191,643,969
5. Step 5: Solve for x
   x = 6,191,643,969/53,142
6. Step 6: Final answer
   x = 116,511.31