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Finding the Fourth Proportional to 8.54, 12.80 and 3.20

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Solution

The fourth proportional to 8.54, 12.80 and 3.20 is: 4.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    8.54 : 12.80 = 3.20 : x
  2. Step 2: Convert to fraction form
    8.54/12.80 = 3.20/x
  3. Step 3: Cross multiply
    8.54x = 12.80 × 3.20
  4. Step 4: Simplify right side
    8.54x = 40.88
  5. Step 5: Solve for x
    x = 40.88/8.54
  6. Step 6: Final answer
    x = 4.79

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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.