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Finding the Fourth Proportional to 90.67, 135.90 and 69.25

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Solution

The fourth proportional to 90.67, 135.90 and 69.25 is: 103.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.67 : 135.90 = 69.25 : x
  2. Step 2: Convert to fraction form
    90.67/135.90 = 69.25/x
  3. Step 3: Cross multiply
    90.67x = 135.90 × 69.25
  4. Step 4: Simplify right side
    90.67x = 9,411.08
  5. Step 5: Solve for x
    x = 9,411.08/90.67
  6. Step 6: Final answer
    x = 103.79

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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.