Finding the Fourth Proportional to 1,978.78, 2,725.15 and 1,935.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,978.78 : 2,725.15 = 1,935.72 : x
2. Step 2: Convert to fraction form
   1,978.78/2,725.15 = 1,935.72/x
3. Step 3: Cross multiply
   1,978.78x = 2,725.15 × 1,935.72
4. Step 4: Simplify right side
   1,978.78x = 5,275,127.36
5. Step 5: Solve for x
   x = 5,275,127.36/1,978.78
6. Step 6: Final answer
   x = 2,665.85