Finding the Fourth Proportional to 1,428.96, 2,142.72 and 606.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,428.96 : 2,142.72 = 606.78 : x
2. Step 2: Convert to fraction form
   1,428.96/2,142.72 = 606.78/x
3. Step 3: Cross multiply
   1,428.96x = 2,142.72 × 606.78
4. Step 4: Simplify right side
   1,428.96x = 1,300,159.64
5. Step 5: Solve for x
   x = 1,300,159.64/1,428.96
6. Step 6: Final answer
   x = 909.86