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Finding the Fourth Proportional to 47.88, 65.78 and 42.12

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Solution

The fourth proportional to 47.88, 65.78 and 42.12 is: 57.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    47.88 : 65.78 = 42.12 : x
  2. Step 2: Convert to fraction form
    47.88/65.78 = 42.12/x
  3. Step 3: Cross multiply
    47.88x = 65.78 × 42.12
  4. Step 4: Simplify right side
    47.88x = 2,770.65
  5. Step 5: Solve for x
    x = 2,770.65/47.88
  6. Step 6: Final answer
    x = 57.87

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.