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Finding the Fourth Proportional to 631.39, 871.46 and 398.47

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Solution

The fourth proportional to 631.39, 871.46 and 398.47 is: 549.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    631.39 : 871.46 = 398.47 : x
  2. Step 2: Convert to fraction form
    631.39/871.46 = 398.47/x
  3. Step 3: Cross multiply
    631.39x = 871.46 × 398.47
  4. Step 4: Simplify right side
    631.39x = 347,250.67
  5. Step 5: Solve for x
    x = 347,250.67/631.39
  6. Step 6: Final answer
    x = 549.98

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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.