Finding the Fourth Proportional to 1,213.89, 1,675.17 and 716.64

Step by Step Solution

1. Step 1: Write the proportion equation
   1,213.89 : 1,675.17 = 716.64 : x
2. Step 2: Convert to fraction form
   1,213.89/1,675.17 = 716.64/x
3. Step 3: Cross multiply
   1,213.89x = 1,675.17 × 716.64
4. Step 4: Simplify right side
   1,213.89x = 1,200,493.83
5. Step 5: Solve for x
   x = 1,200,493.83/1,213.89
6. Step 6: Final answer
   x = 988.96