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Finding the Fourth Proportional to 90.74, 135.49 and 72.25

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Solution

The fourth proportional to 90.74, 135.49 and 72.25 is: 107.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.74 : 135.49 = 72.25 : x
  2. Step 2: Convert to fraction form
    90.74/135.49 = 72.25/x
  3. Step 3: Cross multiply
    90.74x = 135.49 × 72.25
  4. Step 4: Simplify right side
    90.74x = 9,788.63
  5. Step 5: Solve for x
    x = 9,788.63/90.74
  6. Step 6: Final answer
    x = 107.88

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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.