Finding the Fourth Proportional to 28,457.83, 42,691.34 and 10,689.87

Step by Step Solution

1. Step 1: Write the proportion equation
   28,457.83 : 42,691.34 = 10,689.87 : x
2. Step 2: Convert to fraction form
   28,457.83/42,691.34 = 10,689.87/x
3. Step 3: Cross multiply
   28,457.83x = 42,691.34 × 10,689.87
4. Step 4: Simplify right side
   28,457.83x = 456,364,874.73
5. Step 5: Solve for x
   x = 456,364,874.73/28,457.83
6. Step 6: Final answer
   x = 16,036.53