Finding the Fourth Proportional to 7,978.96, 11,973.56 and 3,872.72

Step by Step Solution

1. Step 1: Write the proportion equation
   7,978.96 : 11,973.56 = 3,872.72 : x
2. Step 2: Convert to fraction form
   7,978.96/11,973.56 = 3,872.72/x
3. Step 3: Cross multiply
   7,978.96x = 11,973.56 × 3,872.72
4. Step 4: Simplify right side
   7,978.96x = 46,370,245.28
5. Step 5: Solve for x
   x = 46,370,245.28/7,978.96
6. Step 6: Final answer
   x = 5,811.57