Finding the Fourth Proportional to 1,641.88, 2,265.42 and 978.94

Step by Step Solution

1. Step 1: Write the proportion equation
   1,641.88 : 2,265.42 = 978.94 : x
2. Step 2: Convert to fraction form
   1,641.88/2,265.42 = 978.94/x
3. Step 3: Cross multiply
   1,641.88x = 2,265.42 × 978.94
4. Step 4: Simplify right side
   1,641.88x = 2,217,710.25
5. Step 5: Solve for x
   x = 2,217,710.25/1,641.88
6. Step 6: Final answer
   x = 1,350.71