Finding the Fourth Proportional to 13,111.70, 19,664.78 and 4,227.85

Step by Step Solution

1. Step 1: Write the proportion equation
   13,111.70 : 19,664.78 = 4,227.85 : x
2. Step 2: Convert to fraction form
   13,111.70/19,664.78 = 4,227.85/x
3. Step 3: Cross multiply
   13,111.70x = 19,664.78 × 4,227.85
4. Step 4: Simplify right side
   13,111.70x = 83,139,632.95
5. Step 5: Solve for x
   x = 83,139,632.95/13,111.70
6. Step 6: Final answer
   x = 6,340.87