Finding the Fourth Proportional to 3,880.69, 5,355.42 and 2,112.30

Step by Step Solution

1. Step 1: Write the proportion equation
   3,880.69 : 5,355.42 = 2,112.30 : x
2. Step 2: Convert to fraction form
   3,880.69/5,355.42 = 2,112.30/x
3. Step 3: Cross multiply
   3,880.69x = 5,355.42 × 2,112.30
4. Step 4: Simplify right side
   3,880.69x = 11,312,253.67
5. Step 5: Solve for x
   x = 11,312,253.67/3,880.69
6. Step 6: Final answer
   x = 2,915.01