Finding the Fourth Proportional to 1,641.81, 2,265.39 and 978.73

Step by Step Solution

1. Step 1: Write the proportion equation
   1,641.81 : 2,265.39 = 978.73 : x
2. Step 2: Convert to fraction form
   1,641.81/2,265.39 = 978.73/x
3. Step 3: Cross multiply
   1,641.81x = 2,265.39 × 978.73
4. Step 4: Simplify right side
   1,641.81x = 2,217,197.88
5. Step 5: Solve for x
   x = 2,217,197.88/1,641.81
6. Step 6: Final answer
   x = 1,350.46