Finding the Fourth Proportional to 2,592.56, 3,888.86 and 644.76

Step by Step Solution

1. Step 1: Write the proportion equation
   2,592.56 : 3,888.86 = 644.76 : x
2. Step 2: Convert to fraction form
   2,592.56/3,888.86 = 644.76/x
3. Step 3: Cross multiply
   2,592.56x = 3,888.86 × 644.76
4. Step 4: Simplify right side
   2,592.56x = 2,507,381.78
5. Step 5: Solve for x
   x = 2,507,381.78/2,592.56
6. Step 6: Final answer
   x = 967.15