Finding the Fourth Proportional to 1,978.76, 2,968.86 and 1,209.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,978.76 : 2,968.86 = 1,209.80 : x
2. Step 2: Convert to fraction form
   1,978.76/2,968.86 = 1,209.80/x
3. Step 3: Cross multiply
   1,978.76x = 2,968.86 × 1,209.80
4. Step 4: Simplify right side
   1,978.76x = 3,591,726.83
5. Step 5: Solve for x
   x = 3,591,726.83/1,978.76
6. Step 6: Final answer
   x = 1,815.14