Finding the Fourth Proportional to 1,971.72, 2,955.60 and 1,320.96

Step by Step Solution

1. Step 1: Write the proportion equation
   1,971.72 : 2,955.60 = 1,320.96 : x
2. Step 2: Convert to fraction form
   1,971.72/2,955.60 = 1,320.96/x
3. Step 3: Cross multiply
   1,971.72x = 2,955.60 × 1,320.96
4. Step 4: Simplify right side
   1,971.72x = 3,904,229.38
5. Step 5: Solve for x
   x = 3,904,229.38/1,971.72
6. Step 6: Final answer
   x = 1,980.11