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Finding the Third Proportional to 309 and 611.25

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Solution

The third proportional to 309 and 611.25 is: 1,209.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    309 : 611.25 = 611.25 : x
  2. Step 2: Convert to fraction form
    309/611.25 = 611.25/x
  3. Step 3: Cross multiply
    309x = 611.25 × 611.25
  4. Step 4: Simplify right side
    309x = 373,626.56
  5. Step 5: Solve for x
    x = 373,626.56/309
  6. Step 6: Final answer
    x = 1,209.15

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Why These Related Problems?

These problems maintain the same ratio (1.98) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.