Finding the Fourth Proportional to 1,680.72, 2,318.72 and 972.43

Step by Step Solution

1. Step 1: Write the proportion equation
   1,680.72 : 2,318.72 = 972.43 : x
2. Step 2: Convert to fraction form
   1,680.72/2,318.72 = 972.43/x
3. Step 3: Cross multiply
   1,680.72x = 2,318.72 × 972.43
4. Step 4: Simplify right side
   1,680.72x = 2,254,792.89
5. Step 5: Solve for x
   x = 2,254,792.89/1,680.72
6. Step 6: Final answer
   x = 1,341.56