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Finding the Fourth Proportional to 406.80, 609.12 and 213.48

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Solution

The fourth proportional to 406.80, 609.12 and 213.48 is: 319.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    406.80 : 609.12 = 213.48 : x
  2. Step 2: Convert to fraction form
    406.80/609.12 = 213.48/x
  3. Step 3: Cross multiply
    406.80x = 609.12 × 213.48
  4. Step 4: Simplify right side
    406.80x = 130,034.94
  5. Step 5: Solve for x
    x = 130,034.94/406.80
  6. Step 6: Final answer
    x = 319.65

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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.