Finding the Fourth Proportional to 1,077.30, 1,613.52 and 643.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,077.30 : 1,613.52 = 643.55 : x
2. Step 2: Convert to fraction form
   1,077.30/1,613.52 = 643.55/x
3. Step 3: Cross multiply
   1,077.30x = 1,613.52 × 643.55
4. Step 4: Simplify right side
   1,077.30x = 1,038,372.73
5. Step 5: Solve for x
   x = 1,038,372.73/1,077.30
6. Step 6: Final answer
   x = 963.87