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Finding the Fourth Proportional to 90.29, 123.92 and 87.96

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Solution

The fourth proportional to 90.29, 123.92 and 87.96 is: 120.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.29 : 123.92 = 87.96 : x
  2. Step 2: Convert to fraction form
    90.29/123.92 = 87.96/x
  3. Step 3: Cross multiply
    90.29x = 123.92 × 87.96
  4. Step 4: Simplify right side
    90.29x = 10,900.36
  5. Step 5: Solve for x
    x = 10,900.36/90.29
  6. Step 6: Final answer
    x = 120.72

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.