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Finding the Fourth Proportional to 430.88, 645.48 and 213.80

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Solution

The fourth proportional to 430.88, 645.48 and 213.80 is: 320.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.88 : 645.48 = 213.80 : x
  2. Step 2: Convert to fraction form
    430.88/645.48 = 213.80/x
  3. Step 3: Cross multiply
    430.88x = 645.48 × 213.80
  4. Step 4: Simplify right side
    430.88x = 138,003.62
  5. Step 5: Solve for x
    x = 138,003.62/430.88
  6. Step 6: Final answer
    x = 320.28

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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.