Finding the Fourth Proportional to 1,379.85, 2,070.69 and 918.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.85 : 2,070.69 = 918.15 : x
2. Step 2: Convert to fraction form
   1,379.85/2,070.69 = 918.15/x
3. Step 3: Cross multiply
   1,379.85x = 2,070.69 × 918.15
4. Step 4: Simplify right side
   1,379.85x = 1,901,204.02
5. Step 5: Solve for x
   x = 1,901,204.02/1,379.85
6. Step 6: Final answer
   x = 1,377.83