Finding the Fourth Proportional to 2,538.72, 3,497.31 and 1,978.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,538.72 : 3,497.31 = 1,978.20 : x
2. Step 2: Convert to fraction form
   2,538.72/3,497.31 = 1,978.20/x
3. Step 3: Cross multiply
   2,538.72x = 3,497.31 × 1,978.20
4. Step 4: Simplify right side
   2,538.72x = 6,918,378.64
5. Step 5: Solve for x
   x = 6,918,378.64/2,538.72
6. Step 6: Final answer
   x = 2,725.14