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Finding the Fourth Proportional to 67.28, 100.90 and 19.18

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Solution

The fourth proportional to 67.28, 100.90 and 19.18 is: 28.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    67.28 : 100.90 = 19.18 : x
  2. Step 2: Convert to fraction form
    67.28/100.90 = 19.18/x
  3. Step 3: Cross multiply
    67.28x = 100.90 × 19.18
  4. Step 4: Simplify right side
    67.28x = 1,935.26
  5. Step 5: Solve for x
    x = 1,935.26/67.28
  6. Step 6: Final answer
    x = 28.76

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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.