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Finding the Fourth Proportional to 1.38, 1.90 and 1.38

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Solution

The fourth proportional to 1.38, 1.90 and 1.38 is: 1.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    1.38 : 1.90 = 1.38 : x
  2. Step 2: Convert to fraction form
    1.38/1.90 = 1.38/x
  3. Step 3: Cross multiply
    1.38x = 1.90 × 1.38
  4. Step 4: Simplify right side
    1.38x = 2.61
  5. Step 5: Solve for x
    x = 2.61/1.38
  6. Step 6: Final answer
    x = 1.89

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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.