Finding the Fourth Proportional to 2,567.91, 3,543.70 and 1,388.98

Step by Step Solution

1. Step 1: Write the proportion equation
   2,567.91 : 3,543.70 = 1,388.98 : x
2. Step 2: Convert to fraction form
   2,567.91/3,543.70 = 1,388.98/x
3. Step 3: Cross multiply
   2,567.91x = 3,543.70 × 1,388.98
4. Step 4: Simplify right side
   2,567.91x = 4,922,128.43
5. Step 5: Solve for x
   x = 4,922,128.43/2,567.91
6. Step 6: Final answer
   x = 1,916.78