Finding the Fourth Proportional to 1,978.72, 2,968.06 and 824.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,978.72 : 2,968.06 = 824.20 : x
2. Step 2: Convert to fraction form
   1,978.72/2,968.06 = 824.20/x
3. Step 3: Cross multiply
   1,978.72x = 2,968.06 × 824.20
4. Step 4: Simplify right side
   1,978.72x = 2,446,275.05
5. Step 5: Solve for x
   x = 2,446,275.05/1,978.72
6. Step 6: Final answer
   x = 1,236.29