Finding the Third Proportional to 78,488 and 100,781.50

Step by Step Solution

1. Step 1: Write the proportion equation
   78,488 : 100,781.50 = 100,781.50 : x
2. Step 2: Convert to fraction form
   78,488/100,781.50 = 100,781.50/x
3. Step 3: Cross multiply
   78,488x = 100,781.50 × 100,781.50
4. Step 4: Simplify right side
   78,488x = 10,156,910,742.25
5. Step 5: Solve for x
   x = 10,156,910,742.25/78,488
6. Step 6: Final answer
   x = 129,407.18