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Finding the Fourth Proportional to 865.25, 1,297.47 and 287.72

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Solution

The fourth proportional to 865.25, 1,297.47 and 287.72 is: 431.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    865.25 : 1,297.47 = 287.72 : x
  2. Step 2: Convert to fraction form
    865.25/1,297.47 = 287.72/x
  3. Step 3: Cross multiply
    865.25x = 1,297.47 × 287.72
  4. Step 4: Simplify right side
    865.25x = 373,305.91
  5. Step 5: Solve for x
    x = 373,305.91/865.25
  6. Step 6: Final answer
    x = 431.44

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Half scale
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Double scale
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1.5x scale

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.