Finding the Fourth Proportional to 1,535.10, 2,118.38 and 905.65

Step by Step Solution

1. Step 1: Write the proportion equation
   1,535.10 : 2,118.38 = 905.65 : x
2. Step 2: Convert to fraction form
   1,535.10/2,118.38 = 905.65/x
3. Step 3: Cross multiply
   1,535.10x = 2,118.38 × 905.65
4. Step 4: Simplify right side
   1,535.10x = 1,918,506.32
5. Step 5: Solve for x
   x = 1,918,506.32/1,535.10
6. Step 6: Final answer
   x = 1,249.76