Finding the Fourth Proportional to 2,620.19, 3,932.09 and 978.05

Step by Step Solution

1. Step 1: Write the proportion equation
   2,620.19 : 3,932.09 = 978.05 : x
2. Step 2: Convert to fraction form
   2,620.19/3,932.09 = 978.05/x
3. Step 3: Cross multiply
   2,620.19x = 3,932.09 × 978.05
4. Step 4: Simplify right side
   2,620.19x = 3,845,780.62
5. Step 5: Solve for x
   x = 3,845,780.62/2,620.19
6. Step 6: Final answer
   x = 1,467.75