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Finding the Fourth Proportional to 430.50, 645.60 and 213.96

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Solution

The fourth proportional to 430.50, 645.60 and 213.96 is: 320.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.50 : 645.60 = 213.96 : x
  2. Step 2: Convert to fraction form
    430.50/645.60 = 213.96/x
  3. Step 3: Cross multiply
    430.50x = 645.60 × 213.96
  4. Step 4: Simplify right side
    430.50x = 138,132.58
  5. Step 5: Solve for x
    x = 138,132.58/430.50
  6. Step 6: Final answer
    x = 320.87

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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.