Finding the Fourth Proportional to 12,780.15, 17,636.18 and 7,190.07

Step by Step Solution

1. Step 1: Write the proportion equation
   12,780.15 : 17,636.18 = 7,190.07 : x
2. Step 2: Convert to fraction form
   12,780.15/17,636.18 = 7,190.07/x
3. Step 3: Cross multiply
   12,780.15x = 17,636.18 × 7,190.07
4. Step 4: Simplify right side
   12,780.15x = 126,805,332.78
5. Step 5: Solve for x
   x = 126,805,332.78/12,780.15
6. Step 6: Final answer
   x = 9,922.05