Finding the Fourth Proportional to 1,389.62, 1,917.68 and 760.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.62 : 1,917.68 = 760.15 : x
2. Step 2: Convert to fraction form
   1,389.62/1,917.68 = 760.15/x
3. Step 3: Cross multiply
   1,389.62x = 1,917.68 × 760.15
4. Step 4: Simplify right side
   1,389.62x = 1,457,723.05
5. Step 5: Solve for x
   x = 1,457,723.05/1,389.62
6. Step 6: Final answer
   x = 1,049.01