Finding the Fourth Proportional to 8,111.61, 12,164.94 and 4,213.89

Step by Step Solution

1. Step 1: Write the proportion equation
   8,111.61 : 12,164.94 = 4,213.89 : x
2. Step 2: Convert to fraction form
   8,111.61/12,164.94 = 4,213.89/x
3. Step 3: Cross multiply
   8,111.61x = 12,164.94 × 4,213.89
4. Step 4: Simplify right side
   8,111.61x = 51,261,719.02
5. Step 5: Solve for x
   x = 51,261,719.02/8,111.61
6. Step 6: Final answer
   x = 6,319.55