Finding the Fourth Proportional to 1,005.47, 1,387.15 and 585.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,005.47 : 1,387.15 = 585.76 : x
2. Step 2: Convert to fraction form
   1,005.47/1,387.15 = 585.76/x
3. Step 3: Cross multiply
   1,005.47x = 1,387.15 × 585.76
4. Step 4: Simplify right side
   1,005.47x = 812,536.98
5. Step 5: Solve for x
   x = 812,536.98/1,005.47
6. Step 6: Final answer
   x = 808.12