Finding the Fourth Proportional to 1,141.87, 1,575.77 and 644.49

Step by Step Solution

1. Step 1: Write the proportion equation
   1,141.87 : 1,575.77 = 644.49 : x
2. Step 2: Convert to fraction form
   1,141.87/1,575.77 = 644.49/x
3. Step 3: Cross multiply
   1,141.87x = 1,575.77 × 644.49
4. Step 4: Simplify right side
   1,141.87x = 1,015,570.69
5. Step 5: Solve for x
   x = 1,015,570.69/1,141.87
6. Step 6: Final answer
   x = 889.39