Finding the Third Proportional to 51,136 and 78,488

Step by Step Solution

1. Step 1: Write the proportion equation
   51,136 : 78,488 = 78,488 : x
2. Step 2: Convert to fraction form
   51,136/78,488 = 78,488/x
3. Step 3: Cross multiply
   51,136x = 78,488 × 78,488
4. Step 4: Simplify right side
   51,136x = 6,160,366,144
5. Step 5: Solve for x
   x = 6,160,366,144/51,136
6. Step 6: Final answer
   x = 120,470.24