Finding the Fourth Proportional to 42,009.99, 63,011.52 and 13,920.87

Step by Step Solution

1. Step 1: Write the proportion equation
   42,009.99 : 63,011.52 = 13,920.87 : x
2. Step 2: Convert to fraction form
   42,009.99/63,011.52 = 13,920.87/x
3. Step 3: Cross multiply
   42,009.99x = 63,011.52 × 13,920.87
4. Step 4: Simplify right side
   42,009.99x = 877,175,178.42
5. Step 5: Solve for x
   x = 877,175,178.42/42,009.99
6. Step 6: Final answer
   x = 20,880.16