Finding the Fourth Proportional to 1,990.31, 2,981.40 and 947.16

Step by Step Solution

1. Step 1: Write the proportion equation
   1,990.31 : 2,981.40 = 947.16 : x
2. Step 2: Convert to fraction form
   1,990.31/2,981.40 = 947.16/x
3. Step 3: Cross multiply
   1,990.31x = 2,981.40 × 947.16
4. Step 4: Simplify right side
   1,990.31x = 2,823,862.82
5. Step 5: Solve for x
   x = 2,823,862.82/1,990.31
6. Step 6: Final answer
   x = 1,418.81