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Finding the Fourth Proportional to 442.72, 611.05 and 287.20

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Solution

The fourth proportional to 442.72, 611.05 and 287.20 is: 396.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    442.72 : 611.05 = 287.20 : x
  2. Step 2: Convert to fraction form
    442.72/611.05 = 287.20/x
  3. Step 3: Cross multiply
    442.72x = 611.05 × 287.20
  4. Step 4: Simplify right side
    442.72x = 175,489.79
  5. Step 5: Solve for x
    x = 175,489.79/442.72
  6. Step 6: Final answer
    x = 396.39

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.