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Finding the Fourth Proportional to 21, 28.98 and 13.73

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Solution

The fourth proportional to 21, 28.98 and 13.73 is: 18.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    21 : 28.98 = 13.73 : x
  2. Step 2: Convert to fraction form
    21/28.98 = 13.73/x
  3. Step 3: Cross multiply
    21x = 28.98 × 13.73
  4. Step 4: Simplify right side
    21x = 397.90
  5. Step 5: Solve for x
    x = 397.90/21
  6. Step 6: Final answer
    x = 18.95

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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.