Finding the Fourth Proportional to 1,389.22, 1,917.47 and 892.01

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.22 : 1,917.47 = 892.01 : x
2. Step 2: Convert to fraction form
   1,389.22/1,917.47 = 892.01/x
3. Step 3: Cross multiply
   1,389.22x = 1,917.47 × 892.01
4. Step 4: Simplify right side
   1,389.22x = 1,710,402.41
5. Step 5: Solve for x
   x = 1,710,402.41/1,389.22
6. Step 6: Final answer
   x = 1,231.20