Finding the Fourth Proportional to 1,379.63, 1,903.83 and 820.16

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.63 : 1,903.83 = 820.16 : x
2. Step 2: Convert to fraction form
   1,379.63/1,903.83 = 820.16/x
3. Step 3: Cross multiply
   1,379.63x = 1,903.83 × 820.16
4. Step 4: Simplify right side
   1,379.63x = 1,561,450.10
5. Step 5: Solve for x
   x = 1,561,450.10/1,379.63
6. Step 6: Final answer
   x = 1,131.79