Finding the Fourth Proportional to 1,388.78, 1,915.35 and 1,093.58

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.78 : 1,915.35 = 1,093.58 : x
2. Step 2: Convert to fraction form
   1,388.78/1,915.35 = 1,093.58/x
3. Step 3: Cross multiply
   1,388.78x = 1,915.35 × 1,093.58
4. Step 4: Simplify right side
   1,388.78x = 2,094,588.45
5. Step 5: Solve for x
   x = 2,094,588.45/1,388.78
6. Step 6: Final answer
   x = 1,508.22