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Finding the Fourth Proportional to 665.87, 998.88 and 221.15

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Solution

The fourth proportional to 665.87, 998.88 and 221.15 is: 331.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.87 : 998.88 = 221.15 : x
  2. Step 2: Convert to fraction form
    665.87/998.88 = 221.15/x
  3. Step 3: Cross multiply
    665.87x = 998.88 × 221.15
  4. Step 4: Simplify right side
    665.87x = 220,902.31
  5. Step 5: Solve for x
    x = 220,902.31/665.87
  6. Step 6: Final answer
    x = 331.75

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Double scale
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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.