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Finding the Fourth Proportional to 631.17, 871.32 and 421.70

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Solution

The fourth proportional to 631.17, 871.32 and 421.70 is: 582.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    631.17 : 871.32 = 421.70 : x
  2. Step 2: Convert to fraction form
    631.17/871.32 = 421.70/x
  3. Step 3: Cross multiply
    631.17x = 871.32 × 421.70
  4. Step 4: Simplify right side
    631.17x = 367,435.64
  5. Step 5: Solve for x
    x = 367,435.64/631.17
  6. Step 6: Final answer
    x = 582.15

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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.