Finding the Fourth Proportional to 78,209.20, 107,990.84 and 72,238.72

Step by Step Solution

1. Step 1: Write the proportion equation
   78,209.20 : 107,990.84 = 72,238.72 : x
2. Step 2: Convert to fraction form
   78,209.20/107,990.84 = 72,238.72/x
3. Step 3: Cross multiply
   78,209.20x = 107,990.84 × 72,238.72
4. Step 4: Simplify right side
   78,209.20x = 7,801,120,053.32
5. Step 5: Solve for x
   x = 7,801,120,053.32/78,209.20
6. Step 6: Final answer
   x = 99,746.83