Finding the Fourth Proportional to 12,978.02, 19,467.14 and 7,131.44

Step by Step Solution

1. Step 1: Write the proportion equation
   12,978.02 : 19,467.14 = 7,131.44 : x
2. Step 2: Convert to fraction form
   12,978.02/19,467.14 = 7,131.44/x
3. Step 3: Cross multiply
   12,978.02x = 19,467.14 × 7,131.44
4. Step 4: Simplify right side
   12,978.02x = 138,828,753.89
5. Step 5: Solve for x
   x = 138,828,753.89/12,978.02
6. Step 6: Final answer
   x = 10,697.22