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Finding the Fourth Proportional to 428.32, 644.76 and 307.43

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Solution

The fourth proportional to 428.32, 644.76 and 307.43 is: 462.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.32 : 644.76 = 307.43 : x
  2. Step 2: Convert to fraction form
    428.32/644.76 = 307.43/x
  3. Step 3: Cross multiply
    428.32x = 644.76 × 307.43
  4. Step 4: Simplify right side
    428.32x = 198,217.76
  5. Step 5: Solve for x
    x = 198,217.76/428.32
  6. Step 6: Final answer
    x = 462.78

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.