Finding the Fourth Proportional to 1,378.99, 1,904.55 and 936.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,378.99 : 1,904.55 = 936.12 : x
2. Step 2: Convert to fraction form
   1,378.99/1,904.55 = 936.12/x
3. Step 3: Cross multiply
   1,378.99x = 1,904.55 × 936.12
4. Step 4: Simplify right side
   1,378.99x = 1,782,887.35
5. Step 5: Solve for x
   x = 1,782,887.35/1,378.99
6. Step 6: Final answer
   x = 1,292.89