Finding the Fourth Proportional to 1,358.64, 1,872.72 and 916.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,358.64 : 1,872.72 = 916.38 : x
2. Step 2: Convert to fraction form
   1,358.64/1,872.72 = 916.38/x
3. Step 3: Cross multiply
   1,358.64x = 1,872.72 × 916.38
4. Step 4: Simplify right side
   1,358.64x = 1,716,123.15
5. Step 5: Solve for x
   x = 1,716,123.15/1,358.64
6. Step 6: Final answer
   x = 1,263.12