Finding the Fourth Proportional to 1,538.29, 2,123.30 and 908.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,538.29 : 2,123.30 = 908.78 : x
2. Step 2: Convert to fraction form
   1,538.29/2,123.30 = 908.78/x
3. Step 3: Cross multiply
   1,538.29x = 2,123.30 × 908.78
4. Step 4: Simplify right side
   1,538.29x = 1,929,620.15
5. Step 5: Solve for x
   x = 1,929,620.15/1,538.29
6. Step 6: Final answer
   x = 1,254.40