Finding the Fourth Proportional to 9,679.43, 13,356.81 and 5,429.90

Step by Step Solution

1. Step 1: Write the proportion equation
   9,679.43 : 13,356.81 = 5,429.90 : x
2. Step 2: Convert to fraction form
   9,679.43/13,356.81 = 5,429.90/x
3. Step 3: Cross multiply
   9,679.43x = 13,356.81 × 5,429.90
4. Step 4: Simplify right side
   9,679.43x = 72,526,142.62
5. Step 5: Solve for x
   x = 72,526,142.62/9,679.43
6. Step 6: Final answer
   x = 7,492.81