Finding the Fourth Proportional to 13,781.22, 19,018.71 and 7,812.78

Step by Step Solution

1. Step 1: Write the proportion equation
   13,781.22 : 19,018.71 = 7,812.78 : x
2. Step 2: Convert to fraction form
   13,781.22/19,018.71 = 7,812.78/x
3. Step 3: Cross multiply
   13,781.22x = 19,018.71 × 7,812.78
4. Step 4: Simplify right side
   13,781.22x = 148,588,997.11
5. Step 5: Solve for x
   x = 148,588,997.11/13,781.22
6. Step 6: Final answer
   x = 10,781.99