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Finding the Fourth Proportional to 67.80, 101.11 and 67.20

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Solution

The fourth proportional to 67.80, 101.11 and 67.20 is: 100.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    67.80 : 101.11 = 67.20 : x
  2. Step 2: Convert to fraction form
    67.80/101.11 = 67.20/x
  3. Step 3: Cross multiply
    67.80x = 101.11 × 67.20
  4. Step 4: Simplify right side
    67.80x = 6,794.59
  5. Step 5: Solve for x
    x = 6,794.59/67.80
  6. Step 6: Final answer
    x = 100.22

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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.