Finding the Fourth Proportional to 1,339.98, 2,010.69 and 1,278.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,339.98 : 2,010.69 = 1,278.06 : x
2. Step 2: Convert to fraction form
   1,339.98/2,010.69 = 1,278.06/x
3. Step 3: Cross multiply
   1,339.98x = 2,010.69 × 1,278.06
4. Step 4: Simplify right side
   1,339.98x = 2,569,782.46
5. Step 5: Solve for x
   x = 2,569,782.46/1,339.98
6. Step 6: Final answer
   x = 1,917.78