Finding the Fourth Proportional to 1,308.84, 1,806.15 and 711.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,308.84 : 1,806.15 = 711.30 : x
2. Step 2: Convert to fraction form
   1,308.84/1,806.15 = 711.30/x
3. Step 3: Cross multiply
   1,308.84x = 1,806.15 × 711.30
4. Step 4: Simplify right side
   1,308.84x = 1,284,714.50
5. Step 5: Solve for x
   x = 1,284,714.50/1,308.84
6. Step 6: Final answer
   x = 981.57