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Finding the Fourth Proportional to 31.06, 42.82 and 28.61

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Solution

The fourth proportional to 31.06, 42.82 and 28.61 is: 39.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    31.06 : 42.82 = 28.61 : x
  2. Step 2: Convert to fraction form
    31.06/42.82 = 28.61/x
  3. Step 3: Cross multiply
    31.06x = 42.82 × 28.61
  4. Step 4: Simplify right side
    31.06x = 1,225.08
  5. Step 5: Solve for x
    x = 1,225.08/31.06
  6. Step 6: Final answer
    x = 39.44

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.