Finding the Fourth Proportional to 1,379.16, 2,065.04 and 830.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.16 : 2,065.04 = 830.56 : x
2. Step 2: Convert to fraction form
   1,379.16/2,065.04 = 830.56/x
3. Step 3: Cross multiply
   1,379.16x = 2,065.04 × 830.56
4. Step 4: Simplify right side
   1,379.16x = 1,715,139.62
5. Step 5: Solve for x
   x = 1,715,139.62/1,379.16
6. Step 6: Final answer
   x = 1,243.61