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Finding the Fourth Proportional to 41.78, 57.68 and 30.85

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Solution

The fourth proportional to 41.78, 57.68 and 30.85 is: 42.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    41.78 : 57.68 = 30.85 : x
  2. Step 2: Convert to fraction form
    41.78/57.68 = 30.85/x
  3. Step 3: Cross multiply
    41.78x = 57.68 × 30.85
  4. Step 4: Simplify right side
    41.78x = 1,779.25
  5. Step 5: Solve for x
    x = 1,779.25/41.78
  6. Step 6: Final answer
    x = 42.58

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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.