Finding the Fourth Proportional to 1,388.42, 1,916.34 and 946.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.42 : 1,916.34 = 946.50 : x
2. Step 2: Convert to fraction form
   1,388.42/1,916.34 = 946.50/x
3. Step 3: Cross multiply
   1,388.42x = 1,916.34 × 946.50
4. Step 4: Simplify right side
   1,388.42x = 1,813,815.81
5. Step 5: Solve for x
   x = 1,813,815.81/1,388.42
6. Step 6: Final answer
   x = 1,306.39