Finding the Fourth Proportional to 1,034.56, 1,426.86 and 640.84

Step by Step Solution

1. Step 1: Write the proportion equation
   1,034.56 : 1,426.86 = 640.84 : x
2. Step 2: Convert to fraction form
   1,034.56/1,426.86 = 640.84/x
3. Step 3: Cross multiply
   1,034.56x = 1,426.86 × 640.84
4. Step 4: Simplify right side
   1,034.56x = 914,388.96
5. Step 5: Solve for x
   x = 914,388.96/1,034.56
6. Step 6: Final answer
   x = 883.84