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Finding the Fourth Proportional to 420.82, 631.26 and 189.66

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Solution

The fourth proportional to 420.82, 631.26 and 189.66 is: 284.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.82 : 631.26 = 189.66 : x
  2. Step 2: Convert to fraction form
    420.82/631.26 = 189.66/x
  3. Step 3: Cross multiply
    420.82x = 631.26 × 189.66
  4. Step 4: Simplify right side
    420.82x = 119,724.77
  5. Step 5: Solve for x
    x = 119,724.77/420.82
  6. Step 6: Final answer
    x = 284.50

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.