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Finding the Fourth Proportional to 644.40, 889.12 and 423.36

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Solution

The fourth proportional to 644.40, 889.12 and 423.36 is: 584.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.40 : 889.12 = 423.36 : x
  2. Step 2: Convert to fraction form
    644.40/889.12 = 423.36/x
  3. Step 3: Cross multiply
    644.40x = 889.12 × 423.36
  4. Step 4: Simplify right side
    644.40x = 376,417.84
  5. Step 5: Solve for x
    x = 376,417.84/644.40
  6. Step 6: Final answer
    x = 584.14

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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.