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Finding the Fourth Proportional to 90.87, 136.37 and 54.69

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Solution

The fourth proportional to 90.87, 136.37 and 54.69 is: 82.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.87 : 136.37 = 54.69 : x
  2. Step 2: Convert to fraction form
    90.87/136.37 = 54.69/x
  3. Step 3: Cross multiply
    90.87x = 136.37 × 54.69
  4. Step 4: Simplify right side
    90.87x = 7,458.08
  5. Step 5: Solve for x
    x = 7,458.08/90.87
  6. Step 6: Final answer
    x = 82.07

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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.