Finding the Fourth Proportional to 1,200.79, 1,657.85 and 920.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,200.79 : 1,657.85 = 920.50 : x
2. Step 2: Convert to fraction form
   1,200.79/1,657.85 = 920.50/x
3. Step 3: Cross multiply
   1,200.79x = 1,657.85 × 920.50
4. Step 4: Simplify right side
   1,200.79x = 1,526,038.03
5. Step 5: Solve for x
   x = 1,526,038.03/1,200.79
6. Step 6: Final answer
   x = 1,270.86