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Finding the Fourth Proportional to 80.16, 120.80 and 76.50

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Solution

The fourth proportional to 80.16, 120.80 and 76.50 is: 115.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.16 : 120.80 = 76.50 : x
  2. Step 2: Convert to fraction form
    80.16/120.80 = 76.50/x
  3. Step 3: Cross multiply
    80.16x = 120.80 × 76.50
  4. Step 4: Simplify right side
    80.16x = 9,241.20
  5. Step 5: Solve for x
    x = 9,241.20/80.16
  6. Step 6: Final answer
    x = 115.28

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.