Finding the Fourth Proportional to 1,379.86, 1,904.24 and 790.58

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.86 : 1,904.24 = 790.58 : x
2. Step 2: Convert to fraction form
   1,379.86/1,904.24 = 790.58/x
3. Step 3: Cross multiply
   1,379.86x = 1,904.24 × 790.58
4. Step 4: Simplify right side
   1,379.86x = 1,505,454.06
5. Step 5: Solve for x
   x = 1,505,454.06/1,379.86
6. Step 6: Final answer
   x = 1,091.02