Finding the Fourth Proportional to 12,111.80, 18,165.87 and 7,759.67

Step by Step Solution

1. Step 1: Write the proportion equation
   12,111.80 : 18,165.87 = 7,759.67 : x
2. Step 2: Convert to fraction form
   12,111.80/18,165.87 = 7,759.67/x
3. Step 3: Cross multiply
   12,111.80x = 18,165.87 × 7,759.67
4. Step 4: Simplify right side
   12,111.80x = 140,961,065.63
5. Step 5: Solve for x
   x = 140,961,065.63/12,111.80
6. Step 6: Final answer
   x = 11,638.33