Finding the Fourth Proportional to 1,379.58, 1,903.95 and 820.14

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.58 : 1,903.95 = 820.14 : x
2. Step 2: Convert to fraction form
   1,379.58/1,903.95 = 820.14/x
3. Step 3: Cross multiply
   1,379.58x = 1,903.95 × 820.14
4. Step 4: Simplify right side
   1,379.58x = 1,561,505.55
5. Step 5: Solve for x
   x = 1,561,505.55/1,379.58
6. Step 6: Final answer
   x = 1,131.87