Finding the Fourth Proportional to 1,538.50, 2,123.13 and 839.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,538.50 : 2,123.13 = 839.88 : x
2. Step 2: Convert to fraction form
   1,538.50/2,123.13 = 839.88/x
3. Step 3: Cross multiply
   1,538.50x = 2,123.13 × 839.88
4. Step 4: Simplify right side
   1,538.50x = 1,783,174.42
5. Step 5: Solve for x
   x = 1,783,174.42/1,538.50
6. Step 6: Final answer
   x = 1,159.03