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Finding the Fourth Proportional to 631.38, 871.42 and 355.38

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Solution

The fourth proportional to 631.38, 871.42 and 355.38 is: 490.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    631.38 : 871.42 = 355.38 : x
  2. Step 2: Convert to fraction form
    631.38/871.42 = 355.38/x
  3. Step 3: Cross multiply
    631.38x = 871.42 × 355.38
  4. Step 4: Simplify right side
    631.38x = 309,680.88
  5. Step 5: Solve for x
    x = 309,680.88/631.38
  6. Step 6: Final answer
    x = 490.49

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Double scale
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1.5x scale

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.