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Finding the Fourth Proportional to 42.39, 63.54 and 18

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Solution

The fourth proportional to 42.39, 63.54 and 18 is: 26.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    42.39 : 63.54 = 18 : x
  2. Step 2: Convert to fraction form
    42.39/63.54 = 18/x
  3. Step 3: Cross multiply
    42.39x = 63.54 × 18
  4. Step 4: Simplify right side
    42.39x = 1,143.72
  5. Step 5: Solve for x
    x = 1,143.72/42.39
  6. Step 6: Final answer
    x = 26.98

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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.