Finding the Fourth Proportional to 1,311.72, 1,965.15 and 1,005.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,311.72 : 1,965.15 = 1,005.54 : x
2. Step 2: Convert to fraction form
   1,311.72/1,965.15 = 1,005.54/x
3. Step 3: Cross multiply
   1,311.72x = 1,965.15 × 1,005.54
4. Step 4: Simplify right side
   1,311.72x = 1,976,036.93
5. Step 5: Solve for x
   x = 1,976,036.93/1,311.72
6. Step 6: Final answer
   x = 1,506.45