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Finding the Fourth Proportional to 31.63, 47.31 and 28.61

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Solution

The fourth proportional to 31.63, 47.31 and 28.61 is: 42.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    31.63 : 47.31 = 28.61 : x
  2. Step 2: Convert to fraction form
    31.63/47.31 = 28.61/x
  3. Step 3: Cross multiply
    31.63x = 47.31 × 28.61
  4. Step 4: Simplify right side
    31.63x = 1,353.54
  5. Step 5: Solve for x
    x = 1,353.54/31.63
  6. Step 6: Final answer
    x = 42.79

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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.