Finding the Fourth Proportional to 12,781.90, 17,638.59 and 7,191.82

Step by Step Solution

1. Step 1: Write the proportion equation
   12,781.90 : 17,638.59 = 7,191.82 : x
2. Step 2: Convert to fraction form
   12,781.90/17,638.59 = 7,191.82/x
3. Step 3: Cross multiply
   12,781.90x = 17,638.59 × 7,191.82
4. Step 4: Simplify right side
   12,781.90x = 126,853,564.33
5. Step 5: Solve for x
   x = 126,853,564.33/12,781.90
6. Step 6: Final answer
   x = 9,924.47