Finding the Fourth Proportional to 1,380.06, 1,904.58 and 790.74

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.06 : 1,904.58 = 790.74 : x
2. Step 2: Convert to fraction form
   1,380.06/1,904.58 = 790.74/x
3. Step 3: Cross multiply
   1,380.06x = 1,904.58 × 790.74
4. Step 4: Simplify right side
   1,380.06x = 1,506,027.59
5. Step 5: Solve for x
   x = 1,506,027.59/1,380.06
6. Step 6: Final answer
   x = 1,091.28