Finding the Fourth Proportional to 8,307.90, 12,459.42 and 3,112.56

Step by Step Solution

1. Step 1: Write the proportion equation
   8,307.90 : 12,459.42 = 3,112.56 : x
2. Step 2: Convert to fraction form
   8,307.90/12,459.42 = 3,112.56/x
3. Step 3: Cross multiply
   8,307.90x = 12,459.42 × 3,112.56
4. Step 4: Simplify right side
   8,307.90x = 38,780,692.32
5. Step 5: Solve for x
   x = 38,780,692.32/8,307.90
6. Step 6: Final answer
   x = 4,667.93