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Finding the Fourth Proportional to 428.84, 641.76 and 307.36

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Solution

The fourth proportional to 428.84, 641.76 and 307.36 is: 459.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.84 : 641.76 = 307.36 : x
  2. Step 2: Convert to fraction form
    428.84/641.76 = 307.36/x
  3. Step 3: Cross multiply
    428.84x = 641.76 × 307.36
  4. Step 4: Simplify right side
    428.84x = 197,251.35
  5. Step 5: Solve for x
    x = 197,251.35/428.84
  6. Step 6: Final answer
    x = 459.96

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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.