Finding the Fourth Proportional to 1,570.20, 2,166.72 and 871.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,570.20 : 2,166.72 = 871.56 : x
2. Step 2: Convert to fraction form
   1,570.20/2,166.72 = 871.56/x
3. Step 3: Cross multiply
   1,570.20x = 2,166.72 × 871.56
4. Step 4: Simplify right side
   1,570.20x = 1,888,426.48
5. Step 5: Solve for x
   x = 1,888,426.48/1,570.20
6. Step 6: Final answer
   x = 1,202.67