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Finding the Fourth Proportional to 425.48, 638.45 and 209.07

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Solution

The fourth proportional to 425.48, 638.45 and 209.07 is: 313.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.48 : 638.45 = 209.07 : x
  2. Step 2: Convert to fraction form
    425.48/638.45 = 209.07/x
  3. Step 3: Cross multiply
    425.48x = 638.45 × 209.07
  4. Step 4: Simplify right side
    425.48x = 133,479.70
  5. Step 5: Solve for x
    x = 133,479.70/425.48
  6. Step 6: Final answer
    x = 313.72

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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.