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Finding the Fourth Proportional to 638.72, 881.28 and 417.60

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Solution

The fourth proportional to 638.72, 881.28 and 417.60 is: 576.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.72 : 881.28 = 417.60 : x
  2. Step 2: Convert to fraction form
    638.72/881.28 = 417.60/x
  3. Step 3: Cross multiply
    638.72x = 881.28 × 417.60
  4. Step 4: Simplify right side
    638.72x = 368,022.53
  5. Step 5: Solve for x
    x = 368,022.53/638.72
  6. Step 6: Final answer
    x = 576.19

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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.