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Finding the Fourth Proportional to 84.42, 126.66 and 79.80

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Solution

The fourth proportional to 84.42, 126.66 and 79.80 is: 119.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.42 : 126.66 = 79.80 : x
  2. Step 2: Convert to fraction form
    84.42/126.66 = 79.80/x
  3. Step 3: Cross multiply
    84.42x = 126.66 × 79.80
  4. Step 4: Simplify right side
    84.42x = 10,107.47
  5. Step 5: Solve for x
    x = 10,107.47/84.42
  6. Step 6: Final answer
    x = 119.73

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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.