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Finding the Fourth Proportional to 430.30, 644.22 and 320.40

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Solution

The fourth proportional to 430.30, 644.22 and 320.40 is: 479.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.30 : 644.22 = 320.40 : x
  2. Step 2: Convert to fraction form
    430.30/644.22 = 320.40/x
  3. Step 3: Cross multiply
    430.30x = 644.22 × 320.40
  4. Step 4: Simplify right side
    430.30x = 206,408.09
  5. Step 5: Solve for x
    x = 206,408.09/430.30
  6. Step 6: Final answer
    x = 479.68

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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.