Finding the Fourth Proportional to 2,620.89, 3,932.90 and 978.59

Step by Step Solution

1. Step 1: Write the proportion equation
   2,620.89 : 3,932.90 = 978.59 : x
2. Step 2: Convert to fraction form
   2,620.89/3,932.90 = 978.59/x
3. Step 3: Cross multiply
   2,620.89x = 3,932.90 × 978.59
4. Step 4: Simplify right side
   2,620.89x = 3,848,699.66
5. Step 5: Solve for x
   x = 3,848,699.66/2,620.89
6. Step 6: Final answer
   x = 1,468.47