Finding the Fourth Proportional to 1,538.18, 2,122.71 and 839.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,538.18 : 2,122.71 = 839.55 : x
2. Step 2: Convert to fraction form
   1,538.18/2,122.71 = 839.55/x
3. Step 3: Cross multiply
   1,538.18x = 2,122.71 × 839.55
4. Step 4: Simplify right side
   1,538.18x = 1,782,121.18
5. Step 5: Solve for x
   x = 1,782,121.18/1,538.18
6. Step 6: Final answer
   x = 1,158.59