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Finding the Fourth Proportional to 90.24, 135 and 79.92

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Solution

The fourth proportional to 90.24, 135 and 79.92 is: 119.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.24 : 135 = 79.92 : x
  2. Step 2: Convert to fraction form
    90.24/135 = 79.92/x
  3. Step 3: Cross multiply
    90.24x = 135 × 79.92
  4. Step 4: Simplify right side
    90.24x = 10,789.20
  5. Step 5: Solve for x
    x = 10,789.20/90.24
  6. Step 6: Final answer
    x = 119.56

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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.