Finding the Fourth Proportional to 7,978.32, 11,016.54 and 7,137.54

Step by Step Solution

1. Step 1: Write the proportion equation
   7,978.32 : 11,016.54 = 7,137.54 : x
2. Step 2: Convert to fraction form
   7,978.32/11,016.54 = 7,137.54/x
3. Step 3: Cross multiply
   7,978.32x = 11,016.54 × 7,137.54
4. Step 4: Simplify right side
   7,978.32x = 78,630,994.91
5. Step 5: Solve for x
   x = 78,630,994.91/7,978.32
6. Step 6: Final answer
   x = 9,855.58