Finding the Fourth Proportional to 1,390.86, 1,920.04 and 801.26

Step by Step Solution

1. Step 1: Write the proportion equation
   1,390.86 : 1,920.04 = 801.26 : x
2. Step 2: Convert to fraction form
   1,390.86/1,920.04 = 801.26/x
3. Step 3: Cross multiply
   1,390.86x = 1,920.04 × 801.26
4. Step 4: Simplify right side
   1,390.86x = 1,538,451.25
5. Step 5: Solve for x
   x = 1,538,451.25/1,390.86
6. Step 6: Final answer
   x = 1,106.12