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Finding the Fourth Proportional to 285.91, 428.72 and 131.70

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Solution

The fourth proportional to 285.91, 428.72 and 131.70 is: 197.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.91 : 428.72 = 131.70 : x
  2. Step 2: Convert to fraction form
    285.91/428.72 = 131.70/x
  3. Step 3: Cross multiply
    285.91x = 428.72 × 131.70
  4. Step 4: Simplify right side
    285.91x = 56,462.42
  5. Step 5: Solve for x
    x = 56,462.42/285.91
  6. Step 6: Final answer
    x = 197.48

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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.