Finding the Fourth Proportional to 1,390.52, 1,918.94 and 801.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,390.52 : 1,918.94 = 801.12 : x
2. Step 2: Convert to fraction form
   1,390.52/1,918.94 = 801.12/x
3. Step 3: Cross multiply
   1,390.52x = 1,918.94 × 801.12
4. Step 4: Simplify right side
   1,390.52x = 1,537,301.21
5. Step 5: Solve for x
   x = 1,537,301.21/1,390.52
6. Step 6: Final answer
   x = 1,105.56