Finding the Fourth Proportional to 1,428.49, 1,969.76 and 930.21

Step by Step Solution

1. Step 1: Write the proportion equation
   1,428.49 : 1,969.76 = 930.21 : x
2. Step 2: Convert to fraction form
   1,428.49/1,969.76 = 930.21/x
3. Step 3: Cross multiply
   1,428.49x = 1,969.76 × 930.21
4. Step 4: Simplify right side
   1,428.49x = 1,832,290.45
5. Step 5: Solve for x
   x = 1,832,290.45/1,428.49
6. Step 6: Final answer
   x = 1,282.68