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Finding the Fourth Proportional to 39.77, 54.90 and 28.17

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Solution

The fourth proportional to 39.77, 54.90 and 28.17 is: 38.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    39.77 : 54.90 = 28.17 : x
  2. Step 2: Convert to fraction form
    39.77/54.90 = 28.17/x
  3. Step 3: Cross multiply
    39.77x = 54.90 × 28.17
  4. Step 4: Simplify right side
    39.77x = 1,546.74
  5. Step 5: Solve for x
    x = 1,546.74/39.77
  6. Step 6: Final answer
    x = 38.89

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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.