Finding the Fourth Proportional to 1,420.35, 1,960.04 and 790.91

Step by Step Solution

1. Step 1: Write the proportion equation
   1,420.35 : 1,960.04 = 790.91 : x
2. Step 2: Convert to fraction form
   1,420.35/1,960.04 = 790.91/x
3. Step 3: Cross multiply
   1,420.35x = 1,960.04 × 790.91
4. Step 4: Simplify right side
   1,420.35x = 1,550,212.83
5. Step 5: Solve for x
   x = 1,550,212.83/1,420.35
6. Step 6: Final answer
   x = 1,091.43