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Finding the Fourth Proportional to 425.42, 638.54 and 415.40

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Solution

The fourth proportional to 425.42, 638.54 and 415.40 is: 623.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.42 : 638.54 = 415.40 : x
  2. Step 2: Convert to fraction form
    425.42/638.54 = 415.40/x
  3. Step 3: Cross multiply
    425.42x = 638.54 × 415.40
  4. Step 4: Simplify right side
    425.42x = 265,249.52
  5. Step 5: Solve for x
    x = 265,249.52/425.42
  6. Step 6: Final answer
    x = 623.50

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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.