Finding the Fourth Proportional to 1,005.18, 1,386.72 and 585.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,005.18 : 1,386.72 = 585.42 : x
2. Step 2: Convert to fraction form
   1,005.18/1,386.72 = 585.42/x
3. Step 3: Cross multiply
   1,005.18x = 1,386.72 × 585.42
4. Step 4: Simplify right side
   1,005.18x = 811,813.62
5. Step 5: Solve for x
   x = 811,813.62/1,005.18
6. Step 6: Final answer
   x = 807.63