Finding the Fourth Proportional to 1,388.92, 1,917.33 and 917.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.92 : 1,917.33 = 917.10 : x
2. Step 2: Convert to fraction form
   1,388.92/1,917.33 = 917.10/x
3. Step 3: Cross multiply
   1,388.92x = 1,917.33 × 917.10
4. Step 4: Simplify right side
   1,388.92x = 1,758,383.34
5. Step 5: Solve for x
   x = 1,758,383.34/1,388.92
6. Step 6: Final answer
   x = 1,266.01