Finding the Fourth Proportional to 1,086.93, 1,499.94 and 644.94

Step by Step Solution

1. Step 1: Write the proportion equation
   1,086.93 : 1,499.94 = 644.94 : x
2. Step 2: Convert to fraction form
   1,086.93/1,499.94 = 644.94/x
3. Step 3: Cross multiply
   1,086.93x = 1,499.94 × 644.94
4. Step 4: Simplify right side
   1,086.93x = 967,371.30
5. Step 5: Solve for x
   x = 967,371.30/1,086.93
6. Step 6: Final answer
   x = 890.00