Finding the Fourth Proportional to 1,072.16, 1,606.89 and 913.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,072.16 : 1,606.89 = 913.76 : x
2. Step 2: Convert to fraction form
   1,072.16/1,606.89 = 913.76/x
3. Step 3: Cross multiply
   1,072.16x = 1,606.89 × 913.76
4. Step 4: Simplify right side
   1,072.16x = 1,468,311.81
5. Step 5: Solve for x
   x = 1,468,311.81/1,072.16
6. Step 6: Final answer
   x = 1,369.49