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Finding the Fourth Proportional to 285.87, 428.97 and 131.78

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Solution

The fourth proportional to 285.87, 428.97 and 131.78 is: 197.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.87 : 428.97 = 131.78 : x
  2. Step 2: Convert to fraction form
    285.87/428.97 = 131.78/x
  3. Step 3: Cross multiply
    285.87x = 428.97 × 131.78
  4. Step 4: Simplify right side
    285.87x = 56,526.86
  5. Step 5: Solve for x
    x = 56,526.86/285.87
  6. Step 6: Final answer
    x = 197.74

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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.