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Finding the Fourth Proportional to 814.40, 1,221.44 and 418.88

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Solution

The fourth proportional to 814.40, 1,221.44 and 418.88 is: 628.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    814.40 : 1,221.44 = 418.88 : x
  2. Step 2: Convert to fraction form
    814.40/1,221.44 = 418.88/x
  3. Step 3: Cross multiply
    814.40x = 1,221.44 × 418.88
  4. Step 4: Simplify right side
    814.40x = 511,636.79
  5. Step 5: Solve for x
    x = 511,636.79/814.40
  6. Step 6: Final answer
    x = 628.24

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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.