Finding the Fourth Proportional to 1,141.80, 1,575.72 and 644.46

Step by Step Solution

1. Step 1: Write the proportion equation
   1,141.80 : 1,575.72 = 644.46 : x
2. Step 2: Convert to fraction form
   1,141.80/1,575.72 = 644.46/x
3. Step 3: Cross multiply
   1,141.80x = 1,575.72 × 644.46
4. Step 4: Simplify right side
   1,141.80x = 1,015,488.51
5. Step 5: Solve for x
   x = 1,015,488.51/1,141.80
6. Step 6: Final answer
   x = 889.38