Finding the Fourth Proportional to 1,877.54, 2,815.59 and 644.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,877.54 : 2,815.59 = 644.72 : x
2. Step 2: Convert to fraction form
   1,877.54/2,815.59 = 644.72/x
3. Step 3: Cross multiply
   1,877.54x = 2,815.59 × 644.72
4. Step 4: Simplify right side
   1,877.54x = 1,815,267.18
5. Step 5: Solve for x
   x = 1,815,267.18/1,877.54
6. Step 6: Final answer
   x = 966.83