Finding the Fourth Proportional to 5,784.72, 7,978.80 and 3,992.88

Step by Step Solution

1. Step 1: Write the proportion equation
   5,784.72 : 7,978.80 = 3,992.88 : x
2. Step 2: Convert to fraction form
   5,784.72/7,978.80 = 3,992.88/x
3. Step 3: Cross multiply
   5,784.72x = 7,978.80 × 3,992.88
4. Step 4: Simplify right side
   5,784.72x = 31,858,390.94
5. Step 5: Solve for x
   x = 31,858,390.94/5,784.72
6. Step 6: Final answer
   x = 5,507.34