Finding the Fourth Proportional to 1,978.25, 2,729.71 and 1,138.64

Step by Step Solution

1. Step 1: Write the proportion equation
   1,978.25 : 2,729.71 = 1,138.64 : x
2. Step 2: Convert to fraction form
   1,978.25/2,729.71 = 1,138.64/x
3. Step 3: Cross multiply
   1,978.25x = 2,729.71 × 1,138.64
4. Step 4: Simplify right side
   1,978.25x = 3,108,156.99
5. Step 5: Solve for x
   x = 3,108,156.99/1,978.25
6. Step 6: Final answer
   x = 1,571.16