Finding the Fourth Proportional to 28,614.28, 42,914.86 and 7,839.40

Step by Step Solution

1. Step 1: Write the proportion equation
   28,614.28 : 42,914.86 = 7,839.40 : x
2. Step 2: Convert to fraction form
   28,614.28/42,914.86 = 7,839.40/x
3. Step 3: Cross multiply
   28,614.28x = 42,914.86 × 7,839.40
4. Step 4: Simplify right side
   28,614.28x = 336,426,753.48
5. Step 5: Solve for x
   x = 336,426,753.48/28,614.28
6. Step 6: Final answer
   x = 11,757.30