Finding the Fourth Proportional to 1,143.03, 1,577.52 and 645.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,143.03 : 1,577.52 = 645.69 : x
2. Step 2: Convert to fraction form
   1,143.03/1,577.52 = 645.69/x
3. Step 3: Cross multiply
   1,143.03x = 1,577.52 × 645.69
4. Step 4: Simplify right side
   1,143.03x = 1,018,588.89
5. Step 5: Solve for x
   x = 1,018,588.89/1,143.03
6. Step 6: Final answer
   x = 891.13