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Finding the Fourth Proportional to 21.07, 31.61 and 6.82

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Solution

The fourth proportional to 21.07, 31.61 and 6.82 is: 10.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.07 : 31.61 = 6.82 : x
  2. Step 2: Convert to fraction form
    21.07/31.61 = 6.82/x
  3. Step 3: Cross multiply
    21.07x = 31.61 × 6.82
  4. Step 4: Simplify right side
    21.07x = 215.47
  5. Step 5: Solve for x
    x = 215.47/21.07
  6. Step 6: Final answer
    x = 10.23

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.