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Finding the Fourth Proportional to 80.66, 120.38 and 79.64

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Solution

The fourth proportional to 80.66, 120.38 and 79.64 is: 118.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.66 : 120.38 = 79.64 : x
  2. Step 2: Convert to fraction form
    80.66/120.38 = 79.64/x
  3. Step 3: Cross multiply
    80.66x = 120.38 × 79.64
  4. Step 4: Simplify right side
    80.66x = 9,587.06
  5. Step 5: Solve for x
    x = 9,587.06/80.66
  6. Step 6: Final answer
    x = 118.86

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.