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Finding the Fourth Proportional to 42.20, 58.20 and 30.54

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Solution

The fourth proportional to 42.20, 58.20 and 30.54 is: 42.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    42.20 : 58.20 = 30.54 : x
  2. Step 2: Convert to fraction form
    42.20/58.20 = 30.54/x
  3. Step 3: Cross multiply
    42.20x = 58.20 × 30.54
  4. Step 4: Simplify right side
    42.20x = 1,777.43
  5. Step 5: Solve for x
    x = 1,777.43/42.20
  6. Step 6: Final answer
    x = 42.12

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.