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Finding the Fourth Proportional to 631.40, 871.20 and 382.70

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Solution

The fourth proportional to 631.40, 871.20 and 382.70 is: 528.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    631.40 : 871.20 = 382.70 : x
  2. Step 2: Convert to fraction form
    631.40/871.20 = 382.70/x
  3. Step 3: Cross multiply
    631.40x = 871.20 × 382.70
  4. Step 4: Simplify right side
    631.40x = 333,408.24
  5. Step 5: Solve for x
    x = 333,408.24/631.40
  6. Step 6: Final answer
    x = 528.05

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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.