Finding the Fourth Proportional to 9,419.20, 12,998.88 and 5,642.96

Step by Step Solution

1. Step 1: Write the proportion equation
   9,419.20 : 12,998.88 = 5,642.96 : x
2. Step 2: Convert to fraction form
   9,419.20/12,998.88 = 5,642.96/x
3. Step 3: Cross multiply
   9,419.20x = 12,998.88 × 5,642.96
4. Step 4: Simplify right side
   9,419.20x = 73,352,159.88
5. Step 5: Solve for x
   x = 73,352,159.88/9,419.20
6. Step 6: Final answer
   x = 7,787.51