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Finding the Fourth Proportional to 865.10, 1,297.20 and 317.12

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Solution

The fourth proportional to 865.10, 1,297.20 and 317.12 is: 475.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    865.10 : 1,297.20 = 317.12 : x
  2. Step 2: Convert to fraction form
    865.10/1,297.20 = 317.12/x
  3. Step 3: Cross multiply
    865.10x = 1,297.20 × 317.12
  4. Step 4: Simplify right side
    865.10x = 411,368.06
  5. Step 5: Solve for x
    x = 411,368.06/865.10
  6. Step 6: Final answer
    x = 475.52

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Double scale
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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.