Finding the Fourth Proportional to 23,128.91, 31,918.12 and 12,518.77

Step by Step Solution

1. Step 1: Write the proportion equation
   23,128.91 : 31,918.12 = 12,518.77 : x
2. Step 2: Convert to fraction form
   23,128.91/31,918.12 = 12,518.77/x
3. Step 3: Cross multiply
   23,128.91x = 31,918.12 × 12,518.77
4. Step 4: Simplify right side
   23,128.91x = 399,575,474.82
5. Step 5: Solve for x
   x = 399,575,474.82/23,128.91
6. Step 6: Final answer
   x = 17,276.02