Finding the Fourth Proportional to 1,389.63, 1,917.69 and 800.16

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.63 : 1,917.69 = 800.16 : x
2. Step 2: Convert to fraction form
   1,389.63/1,917.69 = 800.16/x
3. Step 3: Cross multiply
   1,389.63x = 1,917.69 × 800.16
4. Step 4: Simplify right side
   1,389.63x = 1,534,458.83
5. Step 5: Solve for x
   x = 1,534,458.83/1,389.63
6. Step 6: Final answer
   x = 1,104.22