Finding the Fourth Proportional to 1,005.74, 1,387.39 and 591.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,005.74 : 1,387.39 = 591.50 : x
2. Step 2: Convert to fraction form
   1,005.74/1,387.39 = 591.50/x
3. Step 3: Cross multiply
   1,005.74x = 1,387.39 × 591.50
4. Step 4: Simplify right side
   1,005.74x = 820,641.19
5. Step 5: Solve for x
   x = 820,641.19/1,005.74
6. Step 6: Final answer
   x = 815.96