Finding the Fourth Proportional to 1,425.60, 1,965.82 and 978.13

Step by Step Solution

1. Step 1: Write the proportion equation
   1,425.60 : 1,965.82 = 978.13 : x
2. Step 2: Convert to fraction form
   1,425.60/1,965.82 = 978.13/x
3. Step 3: Cross multiply
   1,425.60x = 1,965.82 × 978.13
4. Step 4: Simplify right side
   1,425.60x = 1,922,817.31
5. Step 5: Solve for x
   x = 1,922,817.31/1,425.60
6. Step 6: Final answer
   x = 1,348.78