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Finding the Fourth Proportional to 80.28, 120.15 and 64.89

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Solution

The fourth proportional to 80.28, 120.15 and 64.89 is: 97.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.28 : 120.15 = 64.89 : x
  2. Step 2: Convert to fraction form
    80.28/120.15 = 64.89/x
  3. Step 3: Cross multiply
    80.28x = 120.15 × 64.89
  4. Step 4: Simplify right side
    80.28x = 7,796.53
  5. Step 5: Solve for x
    x = 7,796.53/80.28
  6. Step 6: Final answer
    x = 97.12

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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.