Finding the Fourth Proportional to 1,601.76, 2,403.72 and 780.24

Step by Step Solution

1. Step 1: Write the proportion equation
   1,601.76 : 2,403.72 = 780.24 : x
2. Step 2: Convert to fraction form
   1,601.76/2,403.72 = 780.24/x
3. Step 3: Cross multiply
   1,601.76x = 2,403.72 × 780.24
4. Step 4: Simplify right side
   1,601.76x = 1,875,478.49
5. Step 5: Solve for x
   x = 1,875,478.49/1,601.76
6. Step 6: Final answer
   x = 1,170.89