Finding the Fourth Proportional to 5,781.50, 7,978.49 and 3,128.93

Step by Step Solution

1. Step 1: Write the proportion equation
   5,781.50 : 7,978.49 = 3,128.93 : x
2. Step 2: Convert to fraction form
   5,781.50/7,978.49 = 3,128.93/x
3. Step 3: Cross multiply
   5,781.50x = 7,978.49 × 3,128.93
4. Step 4: Simplify right side
   5,781.50x = 24,964,136.72
5. Step 5: Solve for x
   x = 24,964,136.72/5,781.50
6. Step 6: Final answer
   x = 4,317.93