Finding the Fourth Proportional to 1,142.04, 1,575.94 and 644.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,142.04 : 1,575.94 = 644.72 : x
2. Step 2: Convert to fraction form
   1,142.04/1,575.94 = 644.72/x
3. Step 3: Cross multiply
   1,142.04x = 1,575.94 × 644.72
4. Step 4: Simplify right side
   1,142.04x = 1,016,040.04
5. Step 5: Solve for x
   x = 1,016,040.04/1,142.04
6. Step 6: Final answer
   x = 889.67