Finding the Fourth Proportional to 12,091.78, 18,138.48 and 4,298.50

Step by Step Solution

1. Step 1: Write the proportion equation
   12,091.78 : 18,138.48 = 4,298.50 : x
2. Step 2: Convert to fraction form
   12,091.78/18,138.48 = 4,298.50/x
3. Step 3: Cross multiply
   12,091.78x = 18,138.48 × 4,298.50
4. Step 4: Simplify right side
   12,091.78x = 77,968,144.10
5. Step 5: Solve for x
   x = 77,968,144.10/12,091.78
6. Step 6: Final answer
   x = 6,448.03