Finding the Fourth Proportional to 8,969.92, 12,378.71 and 4,991.42

Step by Step Solution

1. Step 1: Write the proportion equation
   8,969.92 : 12,378.71 = 4,991.42 : x
2. Step 2: Convert to fraction form
   8,969.92/12,378.71 = 4,991.42/x
3. Step 3: Cross multiply
   8,969.92x = 12,378.71 × 4,991.42
4. Step 4: Simplify right side
   8,969.92x = 61,787,315.71
5. Step 5: Solve for x
   x = 61,787,315.71/8,969.92
6. Step 6: Final answer
   x = 6,888.28