Finding the Fourth Proportional to 12,678.78, 19,011.90 and 8,002.50

Step by Step Solution

1. Step 1: Write the proportion equation
   12,678.78 : 19,011.90 = 8,002.50 : x
2. Step 2: Convert to fraction form
   12,678.78/19,011.90 = 8,002.50/x
3. Step 3: Cross multiply
   12,678.78x = 19,011.90 × 8,002.50
4. Step 4: Simplify right side
   12,678.78x = 152,142,729.75
5. Step 5: Solve for x
   x = 152,142,729.75/12,678.78
6. Step 6: Final answer
   x = 11,999.79