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Finding the Fourth Proportional to 815.22, 1,221 and 449.22

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Solution

The fourth proportional to 815.22, 1,221 and 449.22 is: 672.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.22 : 1,221 = 449.22 : x
  2. Step 2: Convert to fraction form
    815.22/1,221 = 449.22/x
  3. Step 3: Cross multiply
    815.22x = 1,221 × 449.22
  4. Step 4: Simplify right side
    815.22x = 548,497.62
  5. Step 5: Solve for x
    x = 548,497.62/815.22
  6. Step 6: Final answer
    x = 672.82

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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.