Finding the Fourth Proportional to 1,007.38, 1,390.06 and 587.87

Step by Step Solution

1. Step 1: Write the proportion equation
   1,007.38 : 1,390.06 = 587.87 : x
2. Step 2: Convert to fraction form
   1,007.38/1,390.06 = 587.87/x
3. Step 3: Cross multiply
   1,007.38x = 1,390.06 × 587.87
4. Step 4: Simplify right side
   1,007.38x = 817,174.57
5. Step 5: Solve for x
   x = 817,174.57/1,007.38
6. Step 6: Final answer
   x = 811.19