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Finding the Fourth Proportional to 97.39, 146.81 and 90.78

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Solution

The fourth proportional to 97.39, 146.81 and 90.78 is: 136.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    97.39 : 146.81 = 90.78 : x
  2. Step 2: Convert to fraction form
    97.39/146.81 = 90.78/x
  3. Step 3: Cross multiply
    97.39x = 146.81 × 90.78
  4. Step 4: Simplify right side
    97.39x = 13,327.25
  5. Step 5: Solve for x
    x = 13,327.25/97.39
  6. Step 6: Final answer
    x = 136.85

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.