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Finding the Fourth Proportional to 428, 644.59 and 379.85

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Solution

The fourth proportional to 428, 644.59 and 379.85 is: 572.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    428 : 644.59 = 379.85 : x
  2. Step 2: Convert to fraction form
    428/644.59 = 379.85/x
  3. Step 3: Cross multiply
    428x = 644.59 × 379.85
  4. Step 4: Simplify right side
    428x = 244,845.61
  5. Step 5: Solve for x
    x = 244,845.61/428
  6. Step 6: Final answer
    x = 572.07

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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.