Finding the Fourth Proportional to 7,018.16, 9,678.72 and 5,422.40

Step by Step Solution

1. Step 1: Write the proportion equation
   7,018.16 : 9,678.72 = 5,422.40 : x
2. Step 2: Convert to fraction form
   7,018.16/9,678.72 = 5,422.40/x
3. Step 3: Cross multiply
   7,018.16x = 9,678.72 × 5,422.40
4. Step 4: Simplify right side
   7,018.16x = 52,481,842.93
5. Step 5: Solve for x
   x = 52,481,842.93/7,018.16
6. Step 6: Final answer
   x = 7,478.01