Finding the Fourth Proportional to 1,764.71, 2,648.72 and 840.90

Step by Step Solution

1. Step 1: Write the proportion equation
   1,764.71 : 2,648.72 = 840.90 : x
2. Step 2: Convert to fraction form
   1,764.71/2,648.72 = 840.90/x
3. Step 3: Cross multiply
   1,764.71x = 2,648.72 × 840.90
4. Step 4: Simplify right side
   1,764.71x = 2,227,308.65
5. Step 5: Solve for x
   x = 2,227,308.65/1,764.71
6. Step 6: Final answer
   x = 1,262.14