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Finding the Fourth Proportional to 42.35, 63.79 and 38.78

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Solution

The fourth proportional to 42.35, 63.79 and 38.78 is: 58.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    42.35 : 63.79 = 38.78 : x
  2. Step 2: Convert to fraction form
    42.35/63.79 = 38.78/x
  3. Step 3: Cross multiply
    42.35x = 63.79 × 38.78
  4. Step 4: Simplify right side
    42.35x = 2,473.78
  5. Step 5: Solve for x
    x = 2,473.78/42.35
  6. Step 6: Final answer
    x = 58.41

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.