Finding the Fourth Proportional to 12,139.76, 18,198.78 and 4,742.48

Step by Step Solution

1. Step 1: Write the proportion equation
   12,139.76 : 18,198.78 = 4,742.48 : x
2. Step 2: Convert to fraction form
   12,139.76/18,198.78 = 4,742.48/x
3. Step 3: Cross multiply
   12,139.76x = 18,198.78 × 4,742.48
4. Step 4: Simplify right side
   12,139.76x = 86,307,350.17
5. Step 5: Solve for x
   x = 86,307,350.17/12,139.76
6. Step 6: Final answer
   x = 7,109.48