Finding the Fourth Proportional to 1,428.32, 1,969.76 and 930.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,428.32 : 1,969.76 = 930.78 : x
2. Step 2: Convert to fraction form
   1,428.32/1,969.76 = 930.78/x
3. Step 3: Cross multiply
   1,428.32x = 1,969.76 × 930.78
4. Step 4: Simplify right side
   1,428.32x = 1,833,408.56
5. Step 5: Solve for x
   x = 1,833,408.56/1,428.32
6. Step 6: Final answer
   x = 1,283.62