Finding the Fourth Proportional to 1,137.91, 1,570.29 and 640.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,137.91 : 1,570.29 = 640.54 : x
2. Step 2: Convert to fraction form
   1,137.91/1,570.29 = 640.54/x
3. Step 3: Cross multiply
   1,137.91x = 1,570.29 × 640.54
4. Step 4: Simplify right side
   1,137.91x = 1,005,833.56
5. Step 5: Solve for x
   x = 1,005,833.56/1,137.91
6. Step 6: Final answer
   x = 883.93