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Finding the Fourth Proportional to 721.80, 1,081.92 and 310.60

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Solution

The fourth proportional to 721.80, 1,081.92 and 310.60 is: 465.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.80 : 1,081.92 = 310.60 : x
  2. Step 2: Convert to fraction form
    721.80/1,081.92 = 310.60/x
  3. Step 3: Cross multiply
    721.80x = 1,081.92 × 310.60
  4. Step 4: Simplify right side
    721.80x = 336,044.35
  5. Step 5: Solve for x
    x = 336,044.35/721.80
  6. Step 6: Final answer
    x = 465.56

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.