Finding the Fourth Proportional to 1,388.25, 1,915.79 and 767.25

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.25 : 1,915.79 = 767.25 : x
2. Step 2: Convert to fraction form
   1,388.25/1,915.79 = 767.25/x
3. Step 3: Cross multiply
   1,388.25x = 1,915.79 × 767.25
4. Step 4: Simplify right side
   1,388.25x = 1,469,886.04
5. Step 5: Solve for x
   x = 1,469,886.04/1,388.25
6. Step 6: Final answer
   x = 1,058.81