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Finding the Fourth Proportional to 631.80, 871.58 and 421.76

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Solution

The fourth proportional to 631.80, 871.58 and 421.76 is: 581.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    631.80 : 871.58 = 421.76 : x
  2. Step 2: Convert to fraction form
    631.80/871.58 = 421.76/x
  3. Step 3: Cross multiply
    631.80x = 871.58 × 421.76
  4. Step 4: Simplify right side
    631.80x = 367,597.58
  5. Step 5: Solve for x
    x = 367,597.58/631.80
  6. Step 6: Final answer
    x = 581.83

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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.