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Finding the Fourth Proportional to 42.43, 63.65 and 20.76

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Solution

The fourth proportional to 42.43, 63.65 and 20.76 is: 31.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    42.43 : 63.65 = 20.76 : x
  2. Step 2: Convert to fraction form
    42.43/63.65 = 20.76/x
  3. Step 3: Cross multiply
    42.43x = 63.65 × 20.76
  4. Step 4: Simplify right side
    42.43x = 1,321.37
  5. Step 5: Solve for x
    x = 1,321.37/42.43
  6. Step 6: Final answer
    x = 31.14

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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.