Finding the Fourth Proportional to 14,647.31, 21,978.71 and 7,988.61

Step by Step Solution

1. Step 1: Write the proportion equation
   14,647.31 : 21,978.71 = 7,988.61 : x
2. Step 2: Convert to fraction form
   14,647.31/21,978.71 = 7,988.61/x
3. Step 3: Cross multiply
   14,647.31x = 21,978.71 × 7,988.61
4. Step 4: Simplify right side
   14,647.31x = 175,579,302.55
5. Step 5: Solve for x
   x = 175,579,302.55/14,647.31
6. Step 6: Final answer
   x = 11,987.14