Finding the Fourth Proportional to 1,577.89, 2,177.55 and 980.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,577.89 : 2,177.55 = 980.72 : x
2. Step 2: Convert to fraction form
   1,577.89/2,177.55 = 980.72/x
3. Step 3: Cross multiply
   1,577.89x = 2,177.55 × 980.72
4. Step 4: Simplify right side
   1,577.89x = 2,135,564.11
5. Step 5: Solve for x
   x = 2,135,564.11/1,577.89
6. Step 6: Final answer
   x = 1,353.43