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Finding the Fourth Proportional to 638.64, 956.28 and 419.52

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Solution

The fourth proportional to 638.64, 956.28 and 419.52 is: 628.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.64 : 956.28 = 419.52 : x
  2. Step 2: Convert to fraction form
    638.64/956.28 = 419.52/x
  3. Step 3: Cross multiply
    638.64x = 956.28 × 419.52
  4. Step 4: Simplify right side
    638.64x = 401,178.59
  5. Step 5: Solve for x
    x = 401,178.59/638.64
  6. Step 6: Final answer
    x = 628.18

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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.