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Finding the Fourth Proportional to 40.14, 55.39 and 21.72

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Solution

The fourth proportional to 40.14, 55.39 and 21.72 is: 29.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    40.14 : 55.39 = 21.72 : x
  2. Step 2: Convert to fraction form
    40.14/55.39 = 21.72/x
  3. Step 3: Cross multiply
    40.14x = 55.39 × 21.72
  4. Step 4: Simplify right side
    40.14x = 1,202.99
  5. Step 5: Solve for x
    x = 1,202.99/40.14
  6. Step 6: Final answer
    x = 29.97

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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.