Finding the Fourth Proportional to 1,574.12, 2,171.79 and 910.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,574.12 : 2,171.79 = 910.80 : x
2. Step 2: Convert to fraction form
   1,574.12/2,171.79 = 910.80/x
3. Step 3: Cross multiply
   1,574.12x = 2,171.79 × 910.80
4. Step 4: Simplify right side
   1,574.12x = 1,978,066.33
5. Step 5: Solve for x
   x = 1,978,066.33/1,574.12
6. Step 6: Final answer
   x = 1,256.62