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Finding the Fourth Proportional to 643.90, 888.59 and 349.18

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Solution

The fourth proportional to 643.90, 888.59 and 349.18 is: 481.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.90 : 888.59 = 349.18 : x
  2. Step 2: Convert to fraction form
    643.90/888.59 = 349.18/x
  3. Step 3: Cross multiply
    643.90x = 888.59 × 349.18
  4. Step 4: Simplify right side
    643.90x = 310,277.86
  5. Step 5: Solve for x
    x = 310,277.86/643.90
  6. Step 6: Final answer
    x = 481.87

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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.