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Finding the Fourth Proportional to 815.61, 1,220.97 and 449.29

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Solution

The fourth proportional to 815.61, 1,220.97 and 449.29 is: 672.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.61 : 1,220.97 = 449.29 : x
  2. Step 2: Convert to fraction form
    815.61/1,220.97 = 449.29/x
  3. Step 3: Cross multiply
    815.61x = 1,220.97 × 449.29
  4. Step 4: Simplify right side
    815.61x = 548,569.61
  5. Step 5: Solve for x
    x = 548,569.61/815.61
  6. Step 6: Final answer
    x = 672.59

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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.