Finding the Fourth Proportional to 2,567.71, 3,543.42 and 1,388.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,567.71 : 3,543.42 = 1,388.78 : x
2. Step 2: Convert to fraction form
   2,567.71/3,543.42 = 1,388.78/x
3. Step 3: Cross multiply
   2,567.71x = 3,543.42 × 1,388.78
4. Step 4: Simplify right side
   2,567.71x = 4,921,018.32
5. Step 5: Solve for x
   x = 4,921,018.32/2,567.71
6. Step 6: Final answer
   x = 1,916.50