Finding the Fourth Proportional to 40,687.98, 61,019.01 and 12,979.50

Step by Step Solution

1. Step 1: Write the proportion equation
   40,687.98 : 61,019.01 = 12,979.50 : x
2. Step 2: Convert to fraction form
   40,687.98/61,019.01 = 12,979.50/x
3. Step 3: Cross multiply
   40,687.98x = 61,019.01 × 12,979.50
4. Step 4: Simplify right side
   40,687.98x = 791,996,240.30
5. Step 5: Solve for x
   x = 791,996,240.30/40,687.98
6. Step 6: Final answer
   x = 19,465.12