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Finding the Fourth Proportional to 420.48, 630.81 and 131.92

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Solution

The fourth proportional to 420.48, 630.81 and 131.92 is: 197.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.48 : 630.81 = 131.92 : x
  2. Step 2: Convert to fraction form
    420.48/630.81 = 131.92/x
  3. Step 3: Cross multiply
    420.48x = 630.81 × 131.92
  4. Step 4: Simplify right side
    420.48x = 83,214.88
  5. Step 5: Solve for x
    x = 83,214.88/420.48
  6. Step 6: Final answer
    x = 197.90

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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.