Finding the Fourth Proportional to 1,965.15, 2,945.30 and 990.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,965.15 : 2,945.30 = 990.72 : x
2. Step 2: Convert to fraction form
   1,965.15/2,945.30 = 990.72/x
3. Step 3: Cross multiply
   1,965.15x = 2,945.30 × 990.72
4. Step 4: Simplify right side
   1,965.15x = 2,917,962.66
5. Step 5: Solve for x
   x = 2,917,962.66/1,965.15
6. Step 6: Final answer
   x = 1,484.85