Finding the Fourth Proportional to 7,978.98, 11,007.72 and 5,145.96

Step by Step Solution

1. Step 1: Write the proportion equation
   7,978.98 : 11,007.72 = 5,145.96 : x
2. Step 2: Convert to fraction form
   7,978.98/11,007.72 = 5,145.96/x
3. Step 3: Cross multiply
   7,978.98x = 11,007.72 × 5,145.96
4. Step 4: Simplify right side
   7,978.98x = 56,645,286.81
5. Step 5: Solve for x
   x = 56,645,286.81/7,978.98
6. Step 6: Final answer
   x = 7,099.31