Finding the Fourth Proportional to 1,143.24, 1,577.59 and 645.93

Step by Step Solution

1. Step 1: Write the proportion equation
   1,143.24 : 1,577.59 = 645.93 : x
2. Step 2: Convert to fraction form
   1,143.24/1,577.59 = 645.93/x
3. Step 3: Cross multiply
   1,143.24x = 1,577.59 × 645.93
4. Step 4: Simplify right side
   1,143.24x = 1,019,012.71
5. Step 5: Solve for x
   x = 1,019,012.71/1,143.24
6. Step 6: Final answer
   x = 891.34