Finding the Fourth Proportional to 1,388.14, 1,915.71 and 922.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.14 : 1,915.71 = 922.06 : x
2. Step 2: Convert to fraction form
   1,388.14/1,915.71 = 922.06/x
3. Step 3: Cross multiply
   1,388.14x = 1,915.71 × 922.06
4. Step 4: Simplify right side
   1,388.14x = 1,766,399.56
5. Step 5: Solve for x
   x = 1,766,399.56/1,388.14
6. Step 6: Final answer
   x = 1,272.49