Finding the Fourth Proportional to 1,390.76, 1,919.24 and 801.24

Step by Step Solution

1. Step 1: Write the proportion equation
   1,390.76 : 1,919.24 = 801.24 : x
2. Step 2: Convert to fraction form
   1,390.76/1,919.24 = 801.24/x
3. Step 3: Cross multiply
   1,390.76x = 1,919.24 × 801.24
4. Step 4: Simplify right side
   1,390.76x = 1,537,771.86
5. Step 5: Solve for x
   x = 1,537,771.86/1,390.76
6. Step 6: Final answer
   x = 1,105.71