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Finding the Fourth Proportional to 420.25, 630.39 and 131.68

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Solution

The fourth proportional to 420.25, 630.39 and 131.68 is: 197.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.25 : 630.39 = 131.68 : x
  2. Step 2: Convert to fraction form
    420.25/630.39 = 131.68/x
  3. Step 3: Cross multiply
    420.25x = 630.39 × 131.68
  4. Step 4: Simplify right side
    420.25x = 83,009.76
  5. Step 5: Solve for x
    x = 83,009.76/420.25
  6. Step 6: Final answer
    x = 197.52

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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.