Finding the Fourth Proportional to 28,404.36, 42,612.12 and 8,685.72

Step by Step Solution

1. Step 1: Write the proportion equation
   28,404.36 : 42,612.12 = 8,685.72 : x
2. Step 2: Convert to fraction form
   28,404.36/42,612.12 = 8,685.72/x
3. Step 3: Cross multiply
   28,404.36x = 42,612.12 × 8,685.72
4. Step 4: Simplify right side
   28,404.36x = 370,116,942.93
5. Step 5: Solve for x
   x = 370,116,942.93/28,404.36
6. Step 6: Final answer
   x = 13,030.29