Finding the Fourth Proportional to 1,641.90, 2,265.77 and 978.41

Step by Step Solution

1. Step 1: Write the proportion equation
   1,641.90 : 2,265.77 = 978.41 : x
2. Step 2: Convert to fraction form
   1,641.90/2,265.77 = 978.41/x
3. Step 3: Cross multiply
   1,641.90x = 2,265.77 × 978.41
4. Step 4: Simplify right side
   1,641.90x = 2,216,860.14
5. Step 5: Solve for x
   x = 2,216,860.14/1,641.90
6. Step 6: Final answer
   x = 1,350.18