Finding the Fourth Proportional to 1,428.81, 2,146.81 and 909.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,428.81 : 2,146.81 = 909.05 : x
2. Step 2: Convert to fraction form
   1,428.81/2,146.81 = 909.05/x
3. Step 3: Cross multiply
   1,428.81x = 2,146.81 × 909.05
4. Step 4: Simplify right side
   1,428.81x = 1,951,548.03
5. Step 5: Solve for x
   x = 1,951,548.03/1,428.81
6. Step 6: Final answer
   x = 1,365.86