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Finding the Fourth Proportional to 285.78, 428.38 and 131.82

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Solution

The fourth proportional to 285.78, 428.38 and 131.82 is: 197.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.78 : 428.38 = 131.82 : x
  2. Step 2: Convert to fraction form
    285.78/428.38 = 131.82/x
  3. Step 3: Cross multiply
    285.78x = 428.38 × 131.82
  4. Step 4: Simplify right side
    285.78x = 56,468.72
  5. Step 5: Solve for x
    x = 56,468.72/285.78
  6. Step 6: Final answer
    x = 197.60

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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.