Finding the Fourth Proportional to 9,979.72, 14,941.60 and 5,289.12

Step by Step Solution

1. Step 1: Write the proportion equation
   9,979.72 : 14,941.60 = 5,289.12 : x
2. Step 2: Convert to fraction form
   9,979.72/14,941.60 = 5,289.12/x
3. Step 3: Cross multiply
   9,979.72x = 14,941.60 × 5,289.12
4. Step 4: Simplify right side
   9,979.72x = 79,027,915.39
5. Step 5: Solve for x
   x = 79,027,915.39/9,979.72
6. Step 6: Final answer
   x = 7,918.85