Finding the Fourth Proportional to 1,380.56, 1,904.88 and 790.94

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.56 : 1,904.88 = 790.94 : x
2. Step 2: Convert to fraction form
   1,380.56/1,904.88 = 790.94/x
3. Step 3: Cross multiply
   1,380.56x = 1,904.88 × 790.94
4. Step 4: Simplify right side
   1,380.56x = 1,506,645.79
5. Step 5: Solve for x
   x = 1,506,645.79/1,380.56
6. Step 6: Final answer
   x = 1,091.33