Finding the Fourth Proportional to 1,380.04, 1,904.52 and 790.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.04 : 1,904.52 = 790.60 : x
2. Step 2: Convert to fraction form
   1,380.04/1,904.52 = 790.60/x
3. Step 3: Cross multiply
   1,380.04x = 1,904.52 × 790.60
4. Step 4: Simplify right side
   1,380.04x = 1,505,713.51
5. Step 5: Solve for x
   x = 1,505,713.51/1,380.04
6. Step 6: Final answer
   x = 1,091.07