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Finding the Fourth Proportional to 15.66, 21.60 and 9.20

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Solution

The fourth proportional to 15.66, 21.60 and 9.20 is: 12.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    15.66 : 21.60 = 9.20 : x
  2. Step 2: Convert to fraction form
    15.66/21.60 = 9.20/x
  3. Step 3: Cross multiply
    15.66x = 21.60 × 9.20
  4. Step 4: Simplify right side
    15.66x = 198.61
  5. Step 5: Solve for x
    x = 198.61/15.66
  6. Step 6: Final answer
    x = 12.68

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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.