Finding the Fourth Proportional to 12,780.84, 17,637.18 and 7,191.72

Step by Step Solution

1. Step 1: Write the proportion equation
   12,780.84 : 17,637.18 = 7,191.72 : x
2. Step 2: Convert to fraction form
   12,780.84/17,637.18 = 7,191.72/x
3. Step 3: Cross multiply
   12,780.84x = 17,637.18 × 7,191.72
4. Step 4: Simplify right side
   12,780.84x = 126,841,660.15
5. Step 5: Solve for x
   x = 126,841,660.15/12,780.84
6. Step 6: Final answer
   x = 9,924.36