Finding the Fourth Proportional to 1,007.42, 1,390.72 and 634.58

Step by Step Solution

1. Step 1: Write the proportion equation
   1,007.42 : 1,390.72 = 634.58 : x
2. Step 2: Convert to fraction form
   1,007.42/1,390.72 = 634.58/x
3. Step 3: Cross multiply
   1,007.42x = 1,390.72 × 634.58
4. Step 4: Simplify right side
   1,007.42x = 882,523.10
5. Step 5: Solve for x
   x = 882,523.10/1,007.42
6. Step 6: Final answer
   x = 876.02