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Finding the Fourth Proportional to 665.75, 998.87 and 209.75

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Solution

The fourth proportional to 665.75, 998.87 and 209.75 is: 314.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.75 : 998.87 = 209.75 : x
  2. Step 2: Convert to fraction form
    665.75/998.87 = 209.75/x
  3. Step 3: Cross multiply
    665.75x = 998.87 × 209.75
  4. Step 4: Simplify right side
    665.75x = 209,512.98
  5. Step 5: Solve for x
    x = 209,512.98/665.75
  6. Step 6: Final answer
    x = 314.70

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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.