Finding the Fourth Proportional to 8,135.42, 12,210.15 and 3,978.50

Step by Step Solution

1. Step 1: Write the proportion equation
   8,135.42 : 12,210.15 = 3,978.50 : x
2. Step 2: Convert to fraction form
   8,135.42/12,210.15 = 3,978.50/x
3. Step 3: Cross multiply
   8,135.42x = 12,210.15 × 3,978.50
4. Step 4: Simplify right side
   8,135.42x = 48,578,081.78
5. Step 5: Solve for x
   x = 48,578,081.78/8,135.42
6. Step 6: Final answer
   x = 5,971.18