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Finding the Fourth Proportional to 428.62, 642.86 and 197.50

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Solution

The fourth proportional to 428.62, 642.86 and 197.50 is: 296.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.62 : 642.86 = 197.50 : x
  2. Step 2: Convert to fraction form
    428.62/642.86 = 197.50/x
  3. Step 3: Cross multiply
    428.62x = 642.86 × 197.50
  4. Step 4: Simplify right side
    428.62x = 126,964.85
  5. Step 5: Solve for x
    x = 126,964.85/428.62
  6. Step 6: Final answer
    x = 296.22

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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.