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Finding the Fourth Proportional to 90.57, 135.87 and 42.51

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Solution

The fourth proportional to 90.57, 135.87 and 42.51 is: 63.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.57 : 135.87 = 42.51 : x
  2. Step 2: Convert to fraction form
    90.57/135.87 = 42.51/x
  3. Step 3: Cross multiply
    90.57x = 135.87 × 42.51
  4. Step 4: Simplify right side
    90.57x = 5,775.83
  5. Step 5: Solve for x
    x = 5,775.83/90.57
  6. Step 6: Final answer
    x = 63.77

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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.