Finding the Fourth Proportional to 1,141.67, 1,575.37 and 644.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,141.67 : 1,575.37 = 644.28 : x
2. Step 2: Convert to fraction form
   1,141.67/1,575.37 = 644.28/x
3. Step 3: Cross multiply
   1,141.67x = 1,575.37 × 644.28
4. Step 4: Simplify right side
   1,141.67x = 1,014,979.38
5. Step 5: Solve for x
   x = 1,014,979.38/1,141.67
6. Step 6: Final answer
   x = 889.03