Finding the Fourth Proportional to 1,064.19, 1,468.61 and 644.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,064.19 : 1,468.61 = 644.61 : x
2. Step 2: Convert to fraction form
   1,064.19/1,468.61 = 644.61/x
3. Step 3: Cross multiply
   1,064.19x = 1,468.61 × 644.61
4. Step 4: Simplify right side
   1,064.19x = 946,677.47
5. Step 5: Solve for x
   x = 946,677.47/1,064.19
6. Step 6: Final answer
   x = 889.58