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Finding the Fourth Proportional to 42.78, 59.07 and 30.48

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Solution

The fourth proportional to 42.78, 59.07 and 30.48 is: 42.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    42.78 : 59.07 = 30.48 : x
  2. Step 2: Convert to fraction form
    42.78/59.07 = 30.48/x
  3. Step 3: Cross multiply
    42.78x = 59.07 × 30.48
  4. Step 4: Simplify right side
    42.78x = 1,800.45
  5. Step 5: Solve for x
    x = 1,800.45/42.78
  6. Step 6: Final answer
    x = 42.09

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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.