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Finding the Fourth Proportional to 428.90, 641.88 and 307.96

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Solution

The fourth proportional to 428.90, 641.88 and 307.96 is: 460.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.90 : 641.88 = 307.96 : x
  2. Step 2: Convert to fraction form
    428.90/641.88 = 307.96/x
  3. Step 3: Cross multiply
    428.90x = 641.88 × 307.96
  4. Step 4: Simplify right side
    428.90x = 197,671.76
  5. Step 5: Solve for x
    x = 197,671.76/428.90
  6. Step 6: Final answer
    x = 460.89

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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.