Finding the Fourth Proportional to 9,678.93, 13,356.12 and 5,429.40

Step by Step Solution

1. Step 1: Write the proportion equation
   9,678.93 : 13,356.12 = 5,429.40 : x
2. Step 2: Convert to fraction form
   9,678.93/13,356.12 = 5,429.40/x
3. Step 3: Cross multiply
   9,678.93x = 13,356.12 × 5,429.40
4. Step 4: Simplify right side
   9,678.93x = 72,515,690.78
5. Step 5: Solve for x
   x = 72,515,690.78/9,678.93
6. Step 6: Final answer
   x = 7,492.12