Finding the Fourth Proportional to 2,978.91, 4,111.08 and 1,720.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,978.91 : 4,111.08 = 1,720.20 : x
2. Step 2: Convert to fraction form
   2,978.91/4,111.08 = 1,720.20/x
3. Step 3: Cross multiply
   2,978.91x = 4,111.08 × 1,720.20
4. Step 4: Simplify right side
   2,978.91x = 7,071,879.82
5. Step 5: Solve for x
   x = 7,071,879.82/2,978.91
6. Step 6: Final answer
   x = 2,373.98