Finding the Fourth Proportional to 1,538.49, 2,123.16 and 839.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,538.49 : 2,123.16 = 839.88 : x
2. Step 2: Convert to fraction form
   1,538.49/2,123.16 = 839.88/x
3. Step 3: Cross multiply
   1,538.49x = 2,123.16 × 839.88
4. Step 4: Simplify right side
   1,538.49x = 1,783,199.62
5. Step 5: Solve for x
   x = 1,783,199.62/1,538.49
6. Step 6: Final answer
   x = 1,159.06