Finding the Fourth Proportional to 1,379.59, 1,903.75 and 820.11

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.59 : 1,903.75 = 820.11 : x
2. Step 2: Convert to fraction form
   1,379.59/1,903.75 = 820.11/x
3. Step 3: Cross multiply
   1,379.59x = 1,903.75 × 820.11
4. Step 4: Simplify right side
   1,379.59x = 1,561,284.41
5. Step 5: Solve for x
   x = 1,561,284.41/1,379.59
6. Step 6: Final answer
   x = 1,131.70