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Finding the Fourth Proportional to 420.69, 631.22 and 189.64

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Solution

The fourth proportional to 420.69, 631.22 and 189.64 is: 284.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.69 : 631.22 = 189.64 : x
  2. Step 2: Convert to fraction form
    420.69/631.22 = 189.64/x
  3. Step 3: Cross multiply
    420.69x = 631.22 × 189.64
  4. Step 4: Simplify right side
    420.69x = 119,704.56
  5. Step 5: Solve for x
    x = 119,704.56/420.69
  6. Step 6: Final answer
    x = 284.54

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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.