Finding the Fourth Proportional to 10,871.93, 14,995.50 and 9,978.57

Step by Step Solution

1. Step 1: Write the proportion equation
   10,871.93 : 14,995.50 = 9,978.57 : x
2. Step 2: Convert to fraction form
   10,871.93/14,995.50 = 9,978.57/x
3. Step 3: Cross multiply
   10,871.93x = 14,995.50 × 9,978.57
4. Step 4: Simplify right side
   10,871.93x = 149,633,646.44
5. Step 5: Solve for x
   x = 149,633,646.44/10,871.93
6. Step 6: Final answer
   x = 13,763.30