Finding the Fourth Proportional to 1,213.06, 1,673.98 and 715.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,213.06 : 1,673.98 = 715.72 : x
2. Step 2: Convert to fraction form
   1,213.06/1,673.98 = 715.72/x
3. Step 3: Cross multiply
   1,213.06x = 1,673.98 × 715.72
4. Step 4: Simplify right side
   1,213.06x = 1,198,100.97
5. Step 5: Solve for x
   x = 1,198,100.97/1,213.06
6. Step 6: Final answer
   x = 987.67