Finding the Fourth Proportional to 2,572.15, 3,854.17 and 1,988.57

Step by Step Solution

1. Step 1: Write the proportion equation
   2,572.15 : 3,854.17 = 1,988.57 : x
2. Step 2: Convert to fraction form
   2,572.15/3,854.17 = 1,988.57/x
3. Step 3: Cross multiply
   2,572.15x = 3,854.17 × 1,988.57
4. Step 4: Simplify right side
   2,572.15x = 7,664,276.89
5. Step 5: Solve for x
   x = 7,664,276.89/2,572.15
6. Step 6: Final answer
   x = 2,979.72