Finding the Fourth Proportional to 6,428.10, 8,870.90 and 3,910.32

Step by Step Solution

1. Step 1: Write the proportion equation
   6,428.10 : 8,870.90 = 3,910.32 : x
2. Step 2: Convert to fraction form
   6,428.10/8,870.90 = 3,910.32/x
3. Step 3: Cross multiply
   6,428.10x = 8,870.90 × 3,910.32
4. Step 4: Simplify right side
   6,428.10x = 34,688,057.69
5. Step 5: Solve for x
   x = 34,688,057.69/6,428.10
6. Step 6: Final answer
   x = 5,396.32