Finding the Fourth Proportional to 1,390.53, 1,918.94 and 801.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,390.53 : 1,918.94 = 801.06 : x
2. Step 2: Convert to fraction form
   1,390.53/1,918.94 = 801.06/x
3. Step 3: Cross multiply
   1,390.53x = 1,918.94 × 801.06
4. Step 4: Simplify right side
   1,390.53x = 1,537,179.38
5. Step 5: Solve for x
   x = 1,537,179.38/1,390.53
6. Step 6: Final answer
   x = 1,105.46