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Finding the Fourth Proportional to 27.20, 40.80 and 21.92

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Solution

The fourth proportional to 27.20, 40.80 and 21.92 is: 32.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    27.20 : 40.80 = 21.92 : x
  2. Step 2: Convert to fraction form
    27.20/40.80 = 21.92/x
  3. Step 3: Cross multiply
    27.20x = 40.80 × 21.92
  4. Step 4: Simplify right side
    27.20x = 894.34
  5. Step 5: Solve for x
    x = 894.34/27.20
  6. Step 6: Final answer
    x = 32.88

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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.