Finding the Fourth Proportional to 13,021.59, 17,972.10 and 7,718.25

Step by Step Solution

1. Step 1: Write the proportion equation
   13,021.59 : 17,972.10 = 7,718.25 : x
2. Step 2: Convert to fraction form
   13,021.59/17,972.10 = 7,718.25/x
3. Step 3: Cross multiply
   13,021.59x = 17,972.10 × 7,718.25
4. Step 4: Simplify right side
   13,021.59x = 138,713,160.83
5. Step 5: Solve for x
   x = 138,713,160.83/13,021.59
6. Step 6: Final answer
   x = 10,652.55