Finding the Fourth Proportional to 13,026.42, 17,978.76 and 7,724.16

Step by Step Solution

1. Step 1: Write the proportion equation
   13,026.42 : 17,978.76 = 7,724.16 : x
2. Step 2: Convert to fraction form
   13,026.42/17,978.76 = 7,724.16/x
3. Step 3: Cross multiply
   13,026.42x = 17,978.76 × 7,724.16
4. Step 4: Simplify right side
   13,026.42x = 138,870,818.84
5. Step 5: Solve for x
   x = 138,870,818.84/13,026.42
6. Step 6: Final answer
   x = 10,660.70