Finding the Fourth Proportional to 8,978.56, 13,446.94 and 8,667.16

Step by Step Solution

1. Step 1: Write the proportion equation
   8,978.56 : 13,446.94 = 8,667.16 : x
2. Step 2: Convert to fraction form
   8,978.56/13,446.94 = 8,667.16/x
3. Step 3: Cross multiply
   8,978.56x = 13,446.94 × 8,667.16
4. Step 4: Simplify right side
   8,978.56x = 116,546,780.49
5. Step 5: Solve for x
   x = 116,546,780.49/8,978.56
6. Step 6: Final answer
   x = 12,980.56