Finding the Fourth Proportional to 1,054.16, 1,581.59 and 663.71

Step by Step Solution

1. Step 1: Write the proportion equation
   1,054.16 : 1,581.59 = 663.71 : x
2. Step 2: Convert to fraction form
   1,054.16/1,581.59 = 663.71/x
3. Step 3: Cross multiply
   1,054.16x = 1,581.59 × 663.71
4. Step 4: Simplify right side
   1,054.16x = 1,049,705.87
5. Step 5: Solve for x
   x = 1,049,705.87/1,054.16
6. Step 6: Final answer
   x = 995.78