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Finding the Fourth Proportional to 644.20, 888.96 and 420.19

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Solution

The fourth proportional to 644.20, 888.96 and 420.19 is: 579.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.20 : 888.96 = 420.19 : x
  2. Step 2: Convert to fraction form
    644.20/888.96 = 420.19/x
  3. Step 3: Cross multiply
    644.20x = 888.96 × 420.19
  4. Step 4: Simplify right side
    644.20x = 373,532.10
  5. Step 5: Solve for x
    x = 373,532.10/644.20
  6. Step 6: Final answer
    x = 579.84

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1.5x scale

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.