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Finding the Fourth Proportional to 643.96, 889.40 and 423.89

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Solution

The fourth proportional to 643.96, 889.40 and 423.89 is: 585.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.96 : 889.40 = 423.89 : x
  2. Step 2: Convert to fraction form
    643.96/889.40 = 423.89/x
  3. Step 3: Cross multiply
    643.96x = 889.40 × 423.89
  4. Step 4: Simplify right side
    643.96x = 377,005.33
  5. Step 5: Solve for x
    x = 377,005.33/643.96
  6. Step 6: Final answer
    x = 585.45

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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.