Finding the Fourth Proportional to 13,145.31, 19,686.54 and 7,581.79

Step by Step Solution

1. Step 1: Write the proportion equation
   13,145.31 : 19,686.54 = 7,581.79 : x
2. Step 2: Convert to fraction form
   13,145.31/19,686.54 = 7,581.79/x
3. Step 3: Cross multiply
   13,145.31x = 19,686.54 × 7,581.79
4. Step 4: Simplify right side
   13,145.31x = 149,259,237.46
5. Step 5: Solve for x
   x = 149,259,237.46/13,145.31
6. Step 6: Final answer
   x = 11,354.56