Finding the Fourth Proportional to 1,561.80, 2,155.98 and 972.73

Step by Step Solution

1. Step 1: Write the proportion equation
   1,561.80 : 2,155.98 = 972.73 : x
2. Step 2: Convert to fraction form
   1,561.80/2,155.98 = 972.73/x
3. Step 3: Cross multiply
   1,561.80x = 2,155.98 × 972.73
4. Step 4: Simplify right side
   1,561.80x = 2,097,186.43
5. Step 5: Solve for x
   x = 2,097,186.43/1,561.80
6. Step 6: Final answer
   x = 1,342.80