Finding the Fourth Proportional to 1,389.50, 1,917.44 and 822.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.50 : 1,917.44 = 822.69 : x
2. Step 2: Convert to fraction form
   1,389.50/1,917.44 = 822.69/x
3. Step 3: Cross multiply
   1,389.50x = 1,917.44 × 822.69
4. Step 4: Simplify right side
   1,389.50x = 1,577,454.60
5. Step 5: Solve for x
   x = 1,577,454.60/1,389.50
6. Step 6: Final answer
   x = 1,135.27