Finding the Fourth Proportional to 12,978.47, 19,473.84 and 7,723.86

Step by Step Solution

1. Step 1: Write the proportion equation
   12,978.47 : 19,473.84 = 7,723.86 : x
2. Step 2: Convert to fraction form
   12,978.47/19,473.84 = 7,723.86/x
3. Step 3: Cross multiply
   12,978.47x = 19,473.84 × 7,723.86
4. Step 4: Simplify right side
   12,978.47x = 150,413,213.82
5. Step 5: Solve for x
   x = 150,413,213.82/12,978.47
6. Step 6: Final answer
   x = 11,589.45