Finding the Fourth Proportional to 1,143.42, 1,577.91 and 646.18

Step by Step Solution

1. Step 1: Write the proportion equation
   1,143.42 : 1,577.91 = 646.18 : x
2. Step 2: Convert to fraction form
   1,143.42/1,577.91 = 646.18/x
3. Step 3: Cross multiply
   1,143.42x = 1,577.91 × 646.18
4. Step 4: Simplify right side
   1,143.42x = 1,019,613.88
5. Step 5: Solve for x
   x = 1,019,613.88/1,143.42
6. Step 6: Final answer
   x = 891.72