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Finding the Fourth Proportional to 728.28, 1,005.12 and 417.78

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Solution

The fourth proportional to 728.28, 1,005.12 and 417.78 is: 576.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.28 : 1,005.12 = 417.78 : x
  2. Step 2: Convert to fraction form
    728.28/1,005.12 = 417.78/x
  3. Step 3: Cross multiply
    728.28x = 1,005.12 × 417.78
  4. Step 4: Simplify right side
    728.28x = 419,919.03
  5. Step 5: Solve for x
    x = 419,919.03/728.28
  6. Step 6: Final answer
    x = 576.59

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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.