Finding the Fourth Proportional to 1,087.04, 1,499.43 and 644.63

Step by Step Solution

1. Step 1: Write the proportion equation
   1,087.04 : 1,499.43 = 644.63 : x
2. Step 2: Convert to fraction form
   1,087.04/1,499.43 = 644.63/x
3. Step 3: Cross multiply
   1,087.04x = 1,499.43 × 644.63
4. Step 4: Simplify right side
   1,087.04x = 966,568.86
5. Step 5: Solve for x
   x = 966,568.86/1,087.04
6. Step 6: Final answer
   x = 889.18