Finding the Fourth Proportional to 1,428.46, 1,971.42 and 904.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,428.46 : 1,971.42 = 904.60 : x
2. Step 2: Convert to fraction form
   1,428.46/1,971.42 = 904.60/x
3. Step 3: Cross multiply
   1,428.46x = 1,971.42 × 904.60
4. Step 4: Simplify right side
   1,428.46x = 1,783,346.53
5. Step 5: Solve for x
   x = 1,783,346.53/1,428.46
6. Step 6: Final answer
   x = 1,248.44