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Finding the Fourth Proportional to 631.88, 871.84 and 421.80

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Solution

The fourth proportional to 631.88, 871.84 and 421.80 is: 581.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    631.88 : 871.84 = 421.80 : x
  2. Step 2: Convert to fraction form
    631.88/871.84 = 421.80/x
  3. Step 3: Cross multiply
    631.88x = 871.84 × 421.80
  4. Step 4: Simplify right side
    631.88x = 367,742.11
  5. Step 5: Solve for x
    x = 367,742.11/631.88
  6. Step 6: Final answer
    x = 581.98

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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.