Finding the Fourth Proportional to 28,442.91, 42,686.15 and 12,871.47

Step by Step Solution

1. Step 1: Write the proportion equation
   28,442.91 : 42,686.15 = 12,871.47 : x
2. Step 2: Convert to fraction form
   28,442.91/42,686.15 = 12,871.47/x
3. Step 3: Cross multiply
   28,442.91x = 42,686.15 × 12,871.47
4. Step 4: Simplify right side
   28,442.91x = 549,433,434.78
5. Step 5: Solve for x
   x = 549,433,434.78/28,442.91
6. Step 6: Final answer
   x = 19,317.06