Finding the Fourth Proportional to 1,141.89, 1,575.67 and 644.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,141.89 : 1,575.67 = 644.50 : x
2. Step 2: Convert to fraction form
   1,141.89/1,575.67 = 644.50/x
3. Step 3: Cross multiply
   1,141.89x = 1,575.67 × 644.50
4. Step 4: Simplify right side
   1,141.89x = 1,015,512.02
5. Step 5: Solve for x
   x = 1,015,512.02/1,141.89
6. Step 6: Final answer
   x = 889.33