Finding the Fourth Proportional to 1,338.21, 1,841.45 and 1,005.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,338.21 : 1,841.45 = 1,005.57 : x
2. Step 2: Convert to fraction form
   1,338.21/1,841.45 = 1,005.57/x
3. Step 3: Cross multiply
   1,338.21x = 1,841.45 × 1,005.57
4. Step 4: Simplify right side
   1,338.21x = 1,851,701.85
5. Step 5: Solve for x
   x = 1,851,701.85/1,338.21
6. Step 6: Final answer
   x = 1,383.72