Finding the Fourth Proportional to 1,150.15, 1,587.10 and 645.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,150.15 : 1,587.10 = 645.89 : x
2. Step 2: Convert to fraction form
   1,150.15/1,587.10 = 645.89/x
3. Step 3: Cross multiply
   1,150.15x = 1,587.10 × 645.89
4. Step 4: Simplify right side
   1,150.15x = 1,025,084.82
5. Step 5: Solve for x
   x = 1,025,084.82/1,150.15
6. Step 6: Final answer
   x = 891.26