Finding the Fourth Proportional to 1,390.61, 1,919.74 and 801.03

Step by Step Solution

1. Step 1: Write the proportion equation
   1,390.61 : 1,919.74 = 801.03 : x
2. Step 2: Convert to fraction form
   1,390.61/1,919.74 = 801.03/x
3. Step 3: Cross multiply
   1,390.61x = 1,919.74 × 801.03
4. Step 4: Simplify right side
   1,390.61x = 1,537,765.33
5. Step 5: Solve for x
   x = 1,537,765.33/1,390.61
6. Step 6: Final answer
   x = 1,105.82