Finding the Fourth Proportional to 12,886.38, 17,781.30 and 7,219.98

Step by Step Solution

1. Step 1: Write the proportion equation
   12,886.38 : 17,781.30 = 7,219.98 : x
2. Step 2: Convert to fraction form
   12,886.38/17,781.30 = 7,219.98/x
3. Step 3: Cross multiply
   12,886.38x = 17,781.30 × 7,219.98
4. Step 4: Simplify right side
   12,886.38x = 128,380,630.37
5. Step 5: Solve for x
   x = 128,380,630.37/12,886.38
6. Step 6: Final answer
   x = 9,962.51