Finding the Fourth Proportional to 1,141.09, 1,574.72 and 643.71

Step by Step Solution

1. Step 1: Write the proportion equation
   1,141.09 : 1,574.72 = 643.71 : x
2. Step 2: Convert to fraction form
   1,141.09/1,574.72 = 643.71/x
3. Step 3: Cross multiply
   1,141.09x = 1,574.72 × 643.71
4. Step 4: Simplify right side
   1,141.09x = 1,013,671.73
5. Step 5: Solve for x
   x = 1,013,671.73/1,141.09
6. Step 6: Final answer
   x = 888.34