Finding the Fourth Proportional to 2,585.84, 3,878.72 and 638.02

Step by Step Solution

1. Step 1: Write the proportion equation
   2,585.84 : 3,878.72 = 638.02 : x
2. Step 2: Convert to fraction form
   2,585.84/3,878.72 = 638.02/x
3. Step 3: Cross multiply
   2,585.84x = 3,878.72 × 638.02
4. Step 4: Simplify right side
   2,585.84x = 2,474,700.93
5. Step 5: Solve for x
   x = 2,474,700.93/2,585.84
6. Step 6: Final answer
   x = 957.02