Finding the Fourth Proportional to 28,434.12, 42,651.42 and 10,899.78

Step by Step Solution

1. Step 1: Write the proportion equation
   28,434.12 : 42,651.42 = 10,899.78 : x
2. Step 2: Convert to fraction form
   28,434.12/42,651.42 = 10,899.78/x
3. Step 3: Cross multiply
   28,434.12x = 42,651.42 × 10,899.78
4. Step 4: Simplify right side
   28,434.12x = 464,891,094.69
5. Step 5: Solve for x
   x = 464,891,094.69/28,434.12
6. Step 6: Final answer
   x = 16,349.76