Finding the Fourth Proportional to 78,687.42, 108,589.23 and 42,878.40

Step by Step Solution

1. Step 1: Write the proportion equation
   78,687.42 : 108,589.23 = 42,878.40 : x
2. Step 2: Convert to fraction form
   78,687.42/108,589.23 = 42,878.40/x
3. Step 3: Cross multiply
   78,687.42x = 108,589.23 × 42,878.40
4. Step 4: Simplify right side
   78,687.42x = 4,656,132,439.63
5. Step 5: Solve for x
   x = 4,656,132,439.63/78,687.42
6. Step 6: Final answer
   x = 59,172.51