Finding the Fourth Proportional to 1,138.41, 1,570.98 and 641.04

Step by Step Solution

1. Step 1: Write the proportion equation
   1,138.41 : 1,570.98 = 641.04 : x
2. Step 2: Convert to fraction form
   1,138.41/1,570.98 = 641.04/x
3. Step 3: Cross multiply
   1,138.41x = 1,570.98 × 641.04
4. Step 4: Simplify right side
   1,138.41x = 1,007,061.02
5. Step 5: Solve for x
   x = 1,007,061.02/1,138.41
6. Step 6: Final answer
   x = 884.62