Finding the Fourth Proportional to 1,978.06, 2,730.69 and 1,279.90

Step by Step Solution

1. Step 1: Write the proportion equation
   1,978.06 : 2,730.69 = 1,279.90 : x
2. Step 2: Convert to fraction form
   1,978.06/2,730.69 = 1,279.90/x
3. Step 3: Cross multiply
   1,978.06x = 2,730.69 × 1,279.90
4. Step 4: Simplify right side
   1,978.06x = 3,495,010.13
5. Step 5: Solve for x
   x = 3,495,010.13/1,978.06
6. Step 6: Final answer
   x = 1,766.89