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Finding the Fourth Proportional to 21.14, 31.86 and 18.17

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Solution

The fourth proportional to 21.14, 31.86 and 18.17 is: 27.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.14 : 31.86 = 18.17 : x
  2. Step 2: Convert to fraction form
    21.14/31.86 = 18.17/x
  3. Step 3: Cross multiply
    21.14x = 31.86 × 18.17
  4. Step 4: Simplify right side
    21.14x = 578.74
  5. Step 5: Solve for x
    x = 578.74/21.14
  6. Step 6: Final answer
    x = 27.38

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.