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Finding the Fourth Proportional to 644.28, 888.98 and 419.78

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Solution

The fourth proportional to 644.28, 888.98 and 419.78 is: 579.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.28 : 888.98 = 419.78 : x
  2. Step 2: Convert to fraction form
    644.28/888.98 = 419.78/x
  3. Step 3: Cross multiply
    644.28x = 888.98 × 419.78
  4. Step 4: Simplify right side
    644.28x = 373,176.02
  5. Step 5: Solve for x
    x = 373,176.02/644.28
  6. Step 6: Final answer
    x = 579.21

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.