Finding the Fourth Proportional to 1,081.62, 1,621.50 and 918.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,081.62 : 1,621.50 = 918.15 : x
2. Step 2: Convert to fraction form
   1,081.62/1,621.50 = 918.15/x
3. Step 3: Cross multiply
   1,081.62x = 1,621.50 × 918.15
4. Step 4: Simplify right side
   1,081.62x = 1,488,780.23
5. Step 5: Solve for x
   x = 1,488,780.23/1,081.62
6. Step 6: Final answer
   x = 1,376.44