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Finding the Fourth Proportional to 420.37, 630.94 and 215.09

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Solution

The fourth proportional to 420.37, 630.94 and 215.09 is: 322.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.37 : 630.94 = 215.09 : x
  2. Step 2: Convert to fraction form
    420.37/630.94 = 215.09/x
  3. Step 3: Cross multiply
    420.37x = 630.94 × 215.09
  4. Step 4: Simplify right side
    420.37x = 135,708.88
  5. Step 5: Solve for x
    x = 135,708.88/420.37
  6. Step 6: Final answer
    x = 322.83

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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.