Finding the Fourth Proportional to 3,869.91, 5,805.32 and 1,405.89

Step by Step Solution

1. Step 1: Write the proportion equation
   3,869.91 : 5,805.32 = 1,405.89 : x
2. Step 2: Convert to fraction form
   3,869.91/5,805.32 = 1,405.89/x
3. Step 3: Cross multiply
   3,869.91x = 5,805.32 × 1,405.89
4. Step 4: Simplify right side
   3,869.91x = 8,161,634.31
5. Step 5: Solve for x
   x = 8,161,634.31/3,869.91
6. Step 6: Final answer
   x = 2,109.00