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Finding the Fourth Proportional to 430.45, 645.68 and 213.94

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Solution

The fourth proportional to 430.45, 645.68 and 213.94 is: 320.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.45 : 645.68 = 213.94 : x
  2. Step 2: Convert to fraction form
    430.45/645.68 = 213.94/x
  3. Step 3: Cross multiply
    430.45x = 645.68 × 213.94
  4. Step 4: Simplify right side
    430.45x = 138,135.71
  5. Step 5: Solve for x
    x = 138,135.71/430.45
  6. Step 6: Final answer
    x = 320.91

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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.