Finding the Fourth Proportional to 1,538.42, 2,123.01 and 839.79

Step by Step Solution

1. Step 1: Write the proportion equation
   1,538.42 : 2,123.01 = 839.79 : x
2. Step 2: Convert to fraction form
   1,538.42/2,123.01 = 839.79/x
3. Step 3: Cross multiply
   1,538.42x = 2,123.01 × 839.79
4. Step 4: Simplify right side
   1,538.42x = 1,782,882.57
5. Step 5: Solve for x
   x = 1,782,882.57/1,538.42
6. Step 6: Final answer
   x = 1,158.90