Finding the Fourth Proportional to 12,985.30, 19,499.55 and 7,146.10

Step by Step Solution

1. Step 1: Write the proportion equation
   12,985.30 : 19,499.55 = 7,146.10 : x
2. Step 2: Convert to fraction form
   12,985.30/19,499.55 = 7,146.10/x
3. Step 3: Cross multiply
   12,985.30x = 19,499.55 × 7,146.10
4. Step 4: Simplify right side
   12,985.30x = 139,345,734.26
5. Step 5: Solve for x
   x = 139,345,734.26/12,985.30
6. Step 6: Final answer
   x = 10,731.04