Finding the Fourth Proportional to 12,420.56, 18,630.86 and 3,186.56

Step by Step Solution

1. Step 1: Write the proportion equation
   12,420.56 : 18,630.86 = 3,186.56 : x
2. Step 2: Convert to fraction form
   12,420.56/18,630.86 = 3,186.56/x
3. Step 3: Cross multiply
   12,420.56x = 18,630.86 × 3,186.56
4. Step 4: Simplify right side
   12,420.56x = 59,368,383.89
5. Step 5: Solve for x
   x = 59,368,383.89/12,420.56
6. Step 6: Final answer
   x = 4,779.85