Finding the Fourth Proportional to 1,019.13, 1,520.88 and 909.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,019.13 : 1,520.88 = 909.78 : x
2. Step 2: Convert to fraction form
   1,019.13/1,520.88 = 909.78/x
3. Step 3: Cross multiply
   1,019.13x = 1,520.88 × 909.78
4. Step 4: Simplify right side
   1,019.13x = 1,383,666.21
5. Step 5: Solve for x
   x = 1,383,666.21/1,019.13
6. Step 6: Final answer
   x = 1,357.69