Finding the Fourth Proportional to 2,978.70, 4,108.79 and 1,970.40

Step by Step Solution

1. Step 1: Write the proportion equation
   2,978.70 : 4,108.79 = 1,970.40 : x
2. Step 2: Convert to fraction form
   2,978.70/4,108.79 = 1,970.40/x
3. Step 3: Cross multiply
   2,978.70x = 4,108.79 × 1,970.40
4. Step 4: Simplify right side
   2,978.70x = 8,095,959.82
5. Step 5: Solve for x
   x = 8,095,959.82/2,978.70
6. Step 6: Final answer
   x = 2,717.95