Finding the Fourth Proportional to 3,870.55, 5,808.32 and 1,405.15

Step by Step Solution

1. Step 1: Write the proportion equation
   3,870.55 : 5,808.32 = 1,405.15 : x
2. Step 2: Convert to fraction form
   3,870.55/5,808.32 = 1,405.15/x
3. Step 3: Cross multiply
   3,870.55x = 5,808.32 × 1,405.15
4. Step 4: Simplify right side
   3,870.55x = 8,161,560.85
5. Step 5: Solve for x
   x = 8,161,560.85/3,870.55
6. Step 6: Final answer
   x = 2,108.63