Finding the Fourth Proportional to 1,660.37, 2,291.16 and 978.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,660.37 : 2,291.16 = 978.89 : x
2. Step 2: Convert to fraction form
   1,660.37/2,291.16 = 978.89/x
3. Step 3: Cross multiply
   1,660.37x = 2,291.16 × 978.89
4. Step 4: Simplify right side
   1,660.37x = 2,242,802.41
5. Step 5: Solve for x
   x = 2,242,802.41/1,660.37
6. Step 6: Final answer
   x = 1,350.79