Finding the Fourth Proportional to 1,148.55, 1,585.03 and 644.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,148.55 : 1,585.03 = 644.42 : x
2. Step 2: Convert to fraction form
   1,148.55/1,585.03 = 644.42/x
3. Step 3: Cross multiply
   1,148.55x = 1,585.03 × 644.42
4. Step 4: Simplify right side
   1,148.55x = 1,021,413.89
5. Step 5: Solve for x
   x = 1,021,413.89/1,148.55
6. Step 6: Final answer
   x = 889.31