Finding the Fourth Proportional to 1,538.72, 2,123.35 and 839.96

Step by Step Solution

1. Step 1: Write the proportion equation
   1,538.72 : 2,123.35 = 839.96 : x
2. Step 2: Convert to fraction form
   1,538.72/2,123.35 = 839.96/x
3. Step 3: Cross multiply
   1,538.72x = 2,123.35 × 839.96
4. Step 4: Simplify right side
   1,538.72x = 1,783,516.35
5. Step 5: Solve for x
   x = 1,783,516.35/1,538.72
6. Step 6: Final answer
   x = 1,159.09