Finding the Fourth Proportional to 9,398.19, 12,939.98 and 7,978.94

Step by Step Solution

1. Step 1: Write the proportion equation
   9,398.19 : 12,939.98 = 7,978.94 : x
2. Step 2: Convert to fraction form
   9,398.19/12,939.98 = 7,978.94/x
3. Step 3: Cross multiply
   9,398.19x = 12,939.98 × 7,978.94
4. Step 4: Simplify right side
   9,398.19x = 103,247,324.02
5. Step 5: Solve for x
   x = 103,247,324.02/9,398.19
6. Step 6: Final answer
   x = 10,985.87