Finding the Fourth Proportional to 28,131.55, 42,202.05 and 8,412.10

Step by Step Solution

1. Step 1: Write the proportion equation
   28,131.55 : 42,202.05 = 8,412.10 : x
2. Step 2: Convert to fraction form
   28,131.55/42,202.05 = 8,412.10/x
3. Step 3: Cross multiply
   28,131.55x = 42,202.05 × 8,412.10
4. Step 4: Simplify right side
   28,131.55x = 355,007,864.81
5. Step 5: Solve for x
   x = 355,007,864.81/28,131.55
6. Step 6: Final answer
   x = 12,619.56