Finding the Fourth Proportional to 2,106.72, 3,157.34 and 872.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,106.72 : 3,157.34 = 872.72 : x
2. Step 2: Convert to fraction form
   2,106.72/3,157.34 = 872.72/x
3. Step 3: Cross multiply
   2,106.72x = 3,157.34 × 872.72
4. Step 4: Simplify right side
   2,106.72x = 2,755,473.76
5. Step 5: Solve for x
   x = 2,755,473.76/2,106.72
6. Step 6: Final answer
   x = 1,307.94