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Finding the Fourth Proportional to 641.62, 962.34 and 208.78

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Solution

The fourth proportional to 641.62, 962.34 and 208.78 is: 313.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.62 : 962.34 = 208.78 : x
  2. Step 2: Convert to fraction form
    641.62/962.34 = 208.78/x
  3. Step 3: Cross multiply
    641.62x = 962.34 × 208.78
  4. Step 4: Simplify right side
    641.62x = 200,917.35
  5. Step 5: Solve for x
    x = 200,917.35/641.62
  6. Step 6: Final answer
    x = 313.14

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.