Finding the Fourth Proportional to 1,390.54, 1,918.72 and 893.08

Step by Step Solution

1. Step 1: Write the proportion equation
   1,390.54 : 1,918.72 = 893.08 : x
2. Step 2: Convert to fraction form
   1,390.54/1,918.72 = 893.08/x
3. Step 3: Cross multiply
   1,390.54x = 1,918.72 × 893.08
4. Step 4: Simplify right side
   1,390.54x = 1,713,570.46
5. Step 5: Solve for x
   x = 1,713,570.46/1,390.54
6. Step 6: Final answer
   x = 1,232.31