Finding the Fourth Proportional to 1,961.40, 2,921.16 and 1,938.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,961.40 : 2,921.16 = 1,938.72 : x
2. Step 2: Convert to fraction form
   1,961.40/2,921.16 = 1,938.72/x
3. Step 3: Cross multiply
   1,961.40x = 2,921.16 × 1,938.72
4. Step 4: Simplify right side
   1,961.40x = 5,663,311.32
5. Step 5: Solve for x
   x = 5,663,311.32/1,961.40
6. Step 6: Final answer
   x = 2,887.38