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Finding the Fourth Proportional to 814.38, 1,221.81 and 424.45

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Solution

The fourth proportional to 814.38, 1,221.81 and 424.45 is: 636.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    814.38 : 1,221.81 = 424.45 : x
  2. Step 2: Convert to fraction form
    814.38/1,221.81 = 424.45/x
  3. Step 3: Cross multiply
    814.38x = 1,221.81 × 424.45
  4. Step 4: Simplify right side
    814.38x = 518,597.25
  5. Step 5: Solve for x
    x = 518,597.25/814.38
  6. Step 6: Final answer
    x = 636.80

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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.