Finding the Fourth Proportional to 1,965.72, 2,949.78 and 811.32

Step by Step Solution

1. Step 1: Write the proportion equation
   1,965.72 : 2,949.78 = 811.32 : x
2. Step 2: Convert to fraction form
   1,965.72/2,949.78 = 811.32/x
3. Step 3: Cross multiply
   1,965.72x = 2,949.78 × 811.32
4. Step 4: Simplify right side
   1,965.72x = 2,393,215.51
5. Step 5: Solve for x
   x = 2,393,215.51/1,965.72
6. Step 6: Final answer
   x = 1,217.48