Finding the Third Proportional to 51,189 and 78,415.50

Step by Step Solution

1. Step 1: Write the proportion equation
   51,189 : 78,415.50 = 78,415.50 : x
2. Step 2: Convert to fraction form
   51,189/78,415.50 = 78,415.50/x
3. Step 3: Cross multiply
   51,189x = 78,415.50 × 78,415.50
4. Step 4: Simplify right side
   51,189x = 6,148,990,640.25
5. Step 5: Solve for x
   x = 6,148,990,640.25/51,189
6. Step 6: Final answer
   x = 120,123.28