Finding the Fourth Proportional to 1,008.87, 1,507.89 and 909.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,008.87 : 1,507.89 = 909.81 : x
2. Step 2: Convert to fraction form
   1,008.87/1,507.89 = 909.81/x
3. Step 3: Cross multiply
   1,008.87x = 1,507.89 × 909.81
4. Step 4: Simplify right side
   1,008.87x = 1,371,899.45
5. Step 5: Solve for x
   x = 1,371,899.45/1,008.87
6. Step 6: Final answer
   x = 1,359.84