Finding the Fourth Proportional to 1,428.82, 1,970.45 and 931.27

Step by Step Solution

1. Step 1: Write the proportion equation
   1,428.82 : 1,970.45 = 931.27 : x
2. Step 2: Convert to fraction form
   1,428.82/1,970.45 = 931.27/x
3. Step 3: Cross multiply
   1,428.82x = 1,970.45 × 931.27
4. Step 4: Simplify right side
   1,428.82x = 1,835,020.97
5. Step 5: Solve for x
   x = 1,835,020.97/1,428.82
6. Step 6: Final answer
   x = 1,284.29