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Finding the Fourth Proportional to 728.38, 1,005.18 and 417.88

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Solution

The fourth proportional to 728.38, 1,005.18 and 417.88 is: 576.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.38 : 1,005.18 = 417.88 : x
  2. Step 2: Convert to fraction form
    728.38/1,005.18 = 417.88/x
  3. Step 3: Cross multiply
    728.38x = 1,005.18 × 417.88
  4. Step 4: Simplify right side
    728.38x = 420,044.62
  5. Step 5: Solve for x
    x = 420,044.62/728.38
  6. Step 6: Final answer
    x = 576.68

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.