Finding the Fourth Proportional to 2,123.33, 3,184.99 and 642.55

Step by Step Solution

1. Step 1: Write the proportion equation
   2,123.33 : 3,184.99 = 642.55 : x
2. Step 2: Convert to fraction form
   2,123.33/3,184.99 = 642.55/x
3. Step 3: Cross multiply
   2,123.33x = 3,184.99 × 642.55
4. Step 4: Simplify right side
   2,123.33x = 2,046,511.73
5. Step 5: Solve for x
   x = 2,046,511.73/2,123.33
6. Step 6: Final answer
   x = 963.82