Finding the Fourth Proportional to 1,120.72, 1,679.86 and 470.70

Step by Step Solution

1. Step 1: Write the proportion equation
   1,120.72 : 1,679.86 = 470.70 : x
2. Step 2: Convert to fraction form
   1,120.72/1,679.86 = 470.70/x
3. Step 3: Cross multiply
   1,120.72x = 1,679.86 × 470.70
4. Step 4: Simplify right side
   1,120.72x = 790,710.10
5. Step 5: Solve for x
   x = 790,710.10/1,120.72
6. Step 6: Final answer
   x = 705.54