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Finding the Fourth Proportional to 80.76, 111.38 and 51.66

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Solution

The fourth proportional to 80.76, 111.38 and 51.66 is: 71.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.76 : 111.38 = 51.66 : x
  2. Step 2: Convert to fraction form
    80.76/111.38 = 51.66/x
  3. Step 3: Cross multiply
    80.76x = 111.38 × 51.66
  4. Step 4: Simplify right side
    80.76x = 5,753.89
  5. Step 5: Solve for x
    x = 5,753.89/80.76
  6. Step 6: Final answer
    x = 71.25

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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.