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Finding the Fourth Proportional to 430.36, 645.20 and 213.82

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Solution

The fourth proportional to 430.36, 645.20 and 213.82 is: 320.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.36 : 645.20 = 213.82 : x
  2. Step 2: Convert to fraction form
    430.36/645.20 = 213.82/x
  3. Step 3: Cross multiply
    430.36x = 645.20 × 213.82
  4. Step 4: Simplify right side
    430.36x = 137,956.66
  5. Step 5: Solve for x
    x = 137,956.66/430.36
  6. Step 6: Final answer
    x = 320.56

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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.