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Finding the Fourth Proportional to 63.78, 87.96 and 48.21

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Solution

The fourth proportional to 63.78, 87.96 and 48.21 is: 66.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    63.78 : 87.96 = 48.21 : x
  2. Step 2: Convert to fraction form
    63.78/87.96 = 48.21/x
  3. Step 3: Cross multiply
    63.78x = 87.96 × 48.21
  4. Step 4: Simplify right side
    63.78x = 4,240.55
  5. Step 5: Solve for x
    x = 4,240.55/63.78
  6. Step 6: Final answer
    x = 66.49

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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.