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Finding the Fourth Proportional to 42.63, 63.99 and 38.78

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Solution

The fourth proportional to 42.63, 63.99 and 38.78 is: 58.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    42.63 : 63.99 = 38.78 : x
  2. Step 2: Convert to fraction form
    42.63/63.99 = 38.78/x
  3. Step 3: Cross multiply
    42.63x = 63.99 × 38.78
  4. Step 4: Simplify right side
    42.63x = 2,481.45
  5. Step 5: Solve for x
    x = 2,481.45/42.63
  6. Step 6: Final answer
    x = 58.21

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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.