Finding the Fourth Proportional to 1,573.49, 2,171.81 and 910.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,573.49 : 2,171.81 = 910.78 : x
2. Step 2: Convert to fraction form
   1,573.49/2,171.81 = 910.78/x
3. Step 3: Cross multiply
   1,573.49x = 2,171.81 × 910.78
4. Step 4: Simplify right side
   1,573.49x = 1,978,037.96
5. Step 5: Solve for x
   x = 1,978,037.96/1,573.49
6. Step 6: Final answer
   x = 1,257.10