Finding the Fourth Proportional to 1,355.39, 1,870.12 and 824.64

Step by Step Solution

1. Step 1: Write the proportion equation
   1,355.39 : 1,870.12 = 824.64 : x
2. Step 2: Convert to fraction form
   1,355.39/1,870.12 = 824.64/x
3. Step 3: Cross multiply
   1,355.39x = 1,870.12 × 824.64
4. Step 4: Simplify right side
   1,355.39x = 1,542,175.76
5. Step 5: Solve for x
   x = 1,542,175.76/1,355.39
6. Step 6: Final answer
   x = 1,137.81