Finding the Fourth Proportional to 1,368.72, 1,889.60 and 903.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,368.72 : 1,889.60 = 903.78 : x
2. Step 2: Convert to fraction form
   1,368.72/1,889.60 = 903.78/x
3. Step 3: Cross multiply
   1,368.72x = 1,889.60 × 903.78
4. Step 4: Simplify right side
   1,368.72x = 1,707,782.69
5. Step 5: Solve for x
   x = 1,707,782.69/1,368.72
6. Step 6: Final answer
   x = 1,247.72