Finding the Fourth Proportional to 1,538.21, 2,122.71 and 839.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,538.21 : 2,122.71 = 839.54 : x
2. Step 2: Convert to fraction form
   1,538.21/2,122.71 = 839.54/x
3. Step 3: Cross multiply
   1,538.21x = 2,122.71 × 839.54
4. Step 4: Simplify right side
   1,538.21x = 1,782,099.95
5. Step 5: Solve for x
   x = 1,782,099.95/1,538.21
6. Step 6: Final answer
   x = 1,158.55