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Finding the Fourth Proportional to 434.82, 648.20 and 428.16

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Solution

The fourth proportional to 434.82, 648.20 and 428.16 is: 638.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    434.82 : 648.20 = 428.16 : x
  2. Step 2: Convert to fraction form
    434.82/648.20 = 428.16/x
  3. Step 3: Cross multiply
    434.82x = 648.20 × 428.16
  4. Step 4: Simplify right side
    434.82x = 277,533.31
  5. Step 5: Solve for x
    x = 277,533.31/434.82
  6. Step 6: Final answer
    x = 638.27

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.