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Finding the Fourth Proportional to 20.71, 28.55 and 16.81

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Solution

The fourth proportional to 20.71, 28.55 and 16.81 is: 23.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.71 : 28.55 = 16.81 : x
  2. Step 2: Convert to fraction form
    20.71/28.55 = 16.81/x
  3. Step 3: Cross multiply
    20.71x = 28.55 × 16.81
  4. Step 4: Simplify right side
    20.71x = 479.95
  5. Step 5: Solve for x
    x = 479.95/20.71
  6. Step 6: Final answer
    x = 23.17

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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.