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Finding the Fourth Proportional to 21.25, 31.86 and 9.22

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Solution

The fourth proportional to 21.25, 31.86 and 9.22 is: 13.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.25 : 31.86 = 9.22 : x
  2. Step 2: Convert to fraction form
    21.25/31.86 = 9.22/x
  3. Step 3: Cross multiply
    21.25x = 31.86 × 9.22
  4. Step 4: Simplify right side
    21.25x = 293.75
  5. Step 5: Solve for x
    x = 293.75/21.25
  6. Step 6: Final answer
    x = 13.82

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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.