Finding the Fourth Proportional to 1,116.79, 1,673.69 and 870.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,116.79 : 1,673.69 = 870.30 : x
2. Step 2: Convert to fraction form
   1,116.79/1,673.69 = 870.30/x
3. Step 3: Cross multiply
   1,116.79x = 1,673.69 × 870.30
4. Step 4: Simplify right side
   1,116.79x = 1,456,608.06
5. Step 5: Solve for x
   x = 1,456,608.06/1,116.79
6. Step 6: Final answer
   x = 1,304.28