Finding the Fourth Proportional to 1,389.87, 1,917.82 and 1,053.96

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.87 : 1,917.82 = 1,053.96 : x
2. Step 2: Convert to fraction form
   1,389.87/1,917.82 = 1,053.96/x
3. Step 3: Cross multiply
   1,389.87x = 1,917.82 × 1,053.96
4. Step 4: Simplify right side
   1,389.87x = 2,021,300.30
5. Step 5: Solve for x
   x = 2,021,300.30/1,389.87
6. Step 6: Final answer
   x = 1,454.31