Finding the Fourth Proportional to 1,005.59, 1,501.56 and 865.19

Step by Step Solution

1. Step 1: Write the proportion equation
   1,005.59 : 1,501.56 = 865.19 : x
2. Step 2: Convert to fraction form
   1,005.59/1,501.56 = 865.19/x
3. Step 3: Cross multiply
   1,005.59x = 1,501.56 × 865.19
4. Step 4: Simplify right side
   1,005.59x = 1,299,130.37
5. Step 5: Solve for x
   x = 1,299,130.37/1,005.59
6. Step 6: Final answer
   x = 1,291.91