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Finding the Fourth Proportional to 814.12, 1,221 and 320.56

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Solution

The fourth proportional to 814.12, 1,221 and 320.56 is: 480.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    814.12 : 1,221 = 320.56 : x
  2. Step 2: Convert to fraction form
    814.12/1,221 = 320.56/x
  3. Step 3: Cross multiply
    814.12x = 1,221 × 320.56
  4. Step 4: Simplify right side
    814.12x = 391,403.76
  5. Step 5: Solve for x
    x = 391,403.76/814.12
  6. Step 6: Final answer
    x = 480.77

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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.