Finding the Fourth Proportional to 42,171.99, 58,245.17 and 28,719.87

Step by Step Solution

1. Step 1: Write the proportion equation
   42,171.99 : 58,245.17 = 28,719.87 : x
2. Step 2: Convert to fraction form
   42,171.99/58,245.17 = 28,719.87/x
3. Step 3: Cross multiply
   42,171.99x = 58,245.17 × 28,719.87
4. Step 4: Simplify right side
   42,171.99x = 1,672,793,566.93
5. Step 5: Solve for x
   x = 1,672,793,566.93/42,171.99
6. Step 6: Final answer
   x = 39,665.99