Finding the Fourth Proportional to 1,390.71, 1,919.67 and 801.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,390.71 : 1,919.67 = 801.48 : x
2. Step 2: Convert to fraction form
   1,390.71/1,919.67 = 801.48/x
3. Step 3: Cross multiply
   1,390.71x = 1,919.67 × 801.48
4. Step 4: Simplify right side
   1,390.71x = 1,538,577.11
5. Step 5: Solve for x
   x = 1,538,577.11/1,390.71
6. Step 6: Final answer
   x = 1,106.32