Finding the Fourth Proportional to 5,781.07, 7,977.89 and 3,128.50

Step by Step Solution

1. Step 1: Write the proportion equation
   5,781.07 : 7,977.89 = 3,128.50 : x
2. Step 2: Convert to fraction form
   5,781.07/7,977.89 = 3,128.50/x
3. Step 3: Cross multiply
   5,781.07x = 7,977.89 × 3,128.50
4. Step 4: Simplify right side
   5,781.07x = 24,958,824.22
5. Step 5: Solve for x
   x = 24,958,824.22/5,781.07
6. Step 6: Final answer
   x = 4,317.34