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Finding the Fourth Proportional to 638.70, 956.12 and 391.26

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Solution

The fourth proportional to 638.70, 956.12 and 391.26 is: 585.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.70 : 956.12 = 391.26 : x
  2. Step 2: Convert to fraction form
    638.70/956.12 = 391.26/x
  3. Step 3: Cross multiply
    638.70x = 956.12 × 391.26
  4. Step 4: Simplify right side
    638.70x = 374,091.51
  5. Step 5: Solve for x
    x = 374,091.51/638.70
  6. Step 6: Final answer
    x = 585.71

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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.