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Finding the Fourth Proportional to 21.82, 30.08 and 21.70

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Solution

The fourth proportional to 21.82, 30.08 and 21.70 is: 29.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.82 : 30.08 = 21.70 : x
  2. Step 2: Convert to fraction form
    21.82/30.08 = 21.70/x
  3. Step 3: Cross multiply
    21.82x = 30.08 × 21.70
  4. Step 4: Simplify right side
    21.82x = 652.74
  5. Step 5: Solve for x
    x = 652.74/21.82
  6. Step 6: Final answer
    x = 29.91

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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.