Finding the Fourth Proportional to 42,287.40, 63,434.34 and 18,916.20

Step by Step Solution

1. Step 1: Write the proportion equation
   42,287.40 : 63,434.34 = 18,916.20 : x
2. Step 2: Convert to fraction form
   42,287.40/63,434.34 = 18,916.20/x
3. Step 3: Cross multiply
   42,287.40x = 63,434.34 × 18,916.20
4. Step 4: Simplify right side
   42,287.40x = 1,199,936,662.31
5. Step 5: Solve for x
   x = 1,199,936,662.31/42,287.40
6. Step 6: Final answer
   x = 28,375.75