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Finding the Fourth Proportional to 16.21, 22.35 and 15.81

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Solution

The fourth proportional to 16.21, 22.35 and 15.81 is: 21.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    16.21 : 22.35 = 15.81 : x
  2. Step 2: Convert to fraction form
    16.21/22.35 = 15.81/x
  3. Step 3: Cross multiply
    16.21x = 22.35 × 15.81
  4. Step 4: Simplify right side
    16.21x = 353.35
  5. Step 5: Solve for x
    x = 353.35/16.21
  6. Step 6: Final answer
    x = 21.80

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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.